Fix wxWidgets debug assertion for wxTextCtrl::IsSingleLine() in GTK.

* Fix assertions in Eeschema when editing net labels, electronic rules check,
  and plotting.
* Fix assertion when opening PCB calculator.
* Fix assertions in Pcbnew when changing footprints in footprint properties
  dialog and adding or editing text.

eeschema/dialogs/dialog_edit_label_base.cpp

@@ -37,7 +37,6 @@ DIALOG_LABEL_EDITOR_BASE::DIALOG_LABEL_EDITOR_BASE( wxWindow* parent, wxWindowID
 	bSizeText->Add( m_textLabelSingleLine, 0, wxEXPAND|wxLEFT, 3 );
 	
 	m_textLabelMultiLine = new wxTextCtrl( this, wxID_VALUEMULTI, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE|wxTE_PROCESS_ENTER );
-	m_textLabelMultiLine->SetMaxLength( 0 ); 
 	m_textLabelMultiLine->SetMinSize( wxSize( -1,60 ) );
 	
 	bSizeText->Add( m_textLabelMultiLine, 1, wxEXPAND|wxLEFT, 3 );

eeschema/dialogs/dialog_edit_label_base.fbp

@@ -327,7 +327,7 @@
                                         <property name="max_size"></property>
                                         <property name="maximize_button">0</property>
                                         <property name="maximum_size"></property>
-                                        <property name="maxlength">0</property>
+                                        <property name="maxlength"></property>
                                         <property name="min_size"></property>
                                         <property name="minimize_button">0</property>
                                         <property name="minimum_size">-1,60</property>

eeschema/dialogs/dialog_erc_base.cpp

@@ -80,7 +80,6 @@ DIALOG_ERC_BASE::DIALOG_ERC_BASE( wxWindow* parent, wxWindowID id, const wxStrin
 	bSizerMessages->Add( m_titleMessages, 0, wxRIGHT|wxLEFT, 5 );
 	
 	m_MessagesList = new wxTextCtrl( m_PanelERC, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE|wxTE_READONLY );
-	m_MessagesList->SetMaxLength( 0 ); 
 	bSizerMessages->Add( m_MessagesList, 1, wxEXPAND|wxLEFT, 5 );
 	
 	

eeschema/dialogs/dialog_erc_base.fbp

@@ -1032,7 +1032,7 @@
                                                             <property name="max_size"></property>
                                                             <property name="maximize_button">0</property>
                                                             <property name="maximum_size"></property>
-                                                            <property name="maxlength">0</property>
+                                                            <property name="maxlength"></property>
                                                             <property name="min_size"></property>
                                                             <property name="minimize_button">0</property>
                                                             <property name="minimum_size">-1,-1</property>

eeschema/dialogs/dialog_plot_schematic_base.cpp

@@ -146,7 +146,6 @@ DIALOG_PLOT_SCHEMATIC_BASE::DIALOG_PLOT_SCHEMATIC_BASE( wxWindow* parent, wxWind
 	bSizer4->Add( m_staticText2, 0, wxTOP|wxRIGHT|wxLEFT, 5 );
 	
 	m_MessagesBox = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE );
-	m_MessagesBox->SetMaxLength( 0 ); 
 	m_MessagesBox->SetMinSize( wxSize( -1,80 ) );
 	
 	bSizer4->Add( m_MessagesBox, 1, wxBOTTOM|wxEXPAND|wxLEFT|wxRIGHT, 5 );

eeschema/dialogs/dialog_plot_schematic_base.fbp

@@ -1799,7 +1799,7 @@
                                 <property name="max_size"></property>
                                 <property name="maximize_button">0</property>
                                 <property name="maximum_size"></property>
-                                <property name="maxlength">0</property>
+                                <property name="maxlength"></property>
                                 <property name="min_size"></property>
                                 <property name="minimize_button">0</property>
                                 <property name="minimum_size">-1,80</property>

pcb_calculator/dialogs/pcb_calculator_frame_base.cpp

@@ -1140,7 +1140,6 @@ PCB_CALCULATOR_FRAME_BASE::PCB_CALCULATOR_FRAME_BASE( wxWindow* parent, wxWindow
 	bMiddleSizerAtt->Add( m_staticTextAttMsg, 0, wxTOP|wxRIGHT|wxLEFT, 5 );
 	
 	m_Attenuator_Messages = new wxTextCtrl( m_panelAttenuators, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE|wxTE_READONLY );
-	m_Attenuator_Messages->SetMaxLength( 0 ); 
 	bMiddleSizerAtt->Add( m_Attenuator_Messages, 1, wxEXPAND|wxBOTTOM|wxRIGHT|wxLEFT, 5 );
 	
 	

pcb_calculator/dialogs/pcb_calculator_frame_base.fbp

@@ -16799,7 +16799,7 @@
                                                     <property name="max_size"></property>
                                                     <property name="maximize_button">0</property>
                                                     <property name="maximum_size"></property>
-                                                    <property name="maxlength">0</property>
+                                                    <property name="maxlength"></property>
                                                     <property name="min_size"></property>
                                                     <property name="minimize_button">0</property>
                                                     <property name="minimum_size"></property>

pcbnew/dialogs/dialog_exchange_modules_base.cpp

@@ -87,7 +87,6 @@ DIALOG_EXCHANGE_MODULE_BASE::DIALOG_EXCHANGE_MODULE_BASE( wxWindow* parent, wxWi
 	bMainSizer->Add( m_staticTextMsg, 0, wxTOP|wxRIGHT|wxLEFT, 5 );
 	
 	m_WinMessages = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE|wxTE_READONLY );
-	m_WinMessages->SetMaxLength( 0 ); 
 	m_WinMessages->SetMinSize( wxSize( 450,300 ) );
 	
 	bMainSizer->Add( m_WinMessages, 1, wxEXPAND|wxBOTTOM|wxRIGHT|wxLEFT, 5 );

pcbnew/dialogs/dialog_exchange_modules_base.fbp

@@ -1219,7 +1219,7 @@
                         <property name="max_size"></property>
                         <property name="maximize_button">0</property>
                         <property name="maximum_size"></property>
-                        <property name="maxlength">0</property>
+                        <property name="maxlength"></property>
                         <property name="min_size"></property>
                         <property name="minimize_button">0</property>
                         <property name="minimum_size">450,300</property>

pcbnew/dialogs/dialog_pcb_text_properties_base.cpp

@@ -26,7 +26,6 @@ DIALOG_PCB_TEXT_PROPERTIES_BASE::DIALOG_PCB_TEXT_PROPERTIES_BASE( wxWindow* pare
 	bSizer9->Add( m_TextLabel, 0, wxTOP|wxRIGHT|wxLEFT, 5 );
 	
 	m_TextContentCtrl = new wxTextCtrl( this, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE );
-	m_TextContentCtrl->SetMaxLength( 0 ); 
 	m_TextContentCtrl->SetToolTip( _("Enter the text placed on selected layer.") );
 	m_TextContentCtrl->SetMinSize( wxSize( 400,60 ) );
 	

pcbnew/dialogs/dialog_pcb_text_properties_base.fbp

@@ -218,7 +218,7 @@
                                 <property name="max_size"></property>
                                 <property name="maximize_button">0</property>
                                 <property name="maximum_size"></property>
-                                <property name="maxlength">0</property>
+                                <property name="maxlength"></property>
                                 <property name="min_size"></property>
                                 <property name="minimize_button">0</property>
                                 <property name="minimum_size">400,60</property>