All: fix a very minor issue: when a window is closed mazimized, and later reopened, it was not maximized.

fix an issue created by commit 2954. Gerbview: display now an indicator of layers in use. minor code cleanup.

* Rename EDA_Rect class to EDA_RECT.
* Rename EDA_TextStruct class to EDA_TEXT.
* Remove duplicate Doxygen comments from sch_sheet_path.cpp.

* Fix about dialog escape key termination bug.
* Fix edit hot keys dialog escape key termination bug.
* Set schematic editor component properties dialog default button.
* Fix schematic editor plot DXF dialog escape key termination bug.
* Set PCB editor layers setup dialog default button.
* Set PCB editor swap layers dialog default button.
* Set PCB editor net list dialog default button.
* Add comment to UIPolicy.txt about escape key termination requiring proper
  dialog button IDs.

* Set default button on all dialogs that do not already have a defined
  default button.  The only exception is the EESchema net list dialog
  which needs converted over to wxFormBuilder and due to it's design makes
  setting the default button in any tab other than the default tab
  problematic.
* Fix escape key dialog handling bug in EESchema print post script
  dialog.

* Remove clearance and net class name read only text boxes from PCBNew
  auxiliary tool bar.
* Display full net class information in message panel when an object that
  supports net classes is selected.
* Move coordinate string conversion function to EDA_DRAW_FRAME object and
  made it more versatile.
* Refresh message panel text when units change.

Pcbnew: dialog plot: make message window resizable, add tool tip and remove unused sizers.

Pcbnew: Fix a very minor issue in left toolbar. Add option in dialog bloc to move,copy ... items on invisible layers or not.

* Fix grid select box update bug on context menu.
* Fix via size and track width select box update bugs.
* Fix layer pair indicator button update bug.
* Fix auto track width tool bar control enable bug.
* Fix via size and track width select status bug in context menu.
* Fix layer select box and layer control widget select bug when current
  layer is removed.
* Add virtual function to notify objects derived from EDA_DRAW_FRAME that
  the units setting has changed.
* Coding policy class naming fixes.

Pcbnew: dialog copper zone: fix bug 726999. Remove unwanted resizing of dialog frame when selecting options.

Use UTF-8 encoding only in kicad files. Under Linux, this was already the case. Under Windows, texts with  non ascii characters must be corrected.
This ensure compatibility between platforms.

kicad: fix Russian GOST page reference sheet - add field 24-25

* Old control state handling code completely removed in all applications.
* Factor common control state handlers into EDA_DRAW_FRAME.
* Replaced EDA_ITEM test for newness with IsNew() method.
* Factor vertical right toolbar command handlers out of giant edit command
  switch statement in EESchema and PCBNew.

Tune pcbnew plot dialog. Make actual plotting code independent of dialog widgets and get settings from PCB_PLOT_PARAMS instead.

Pcbnew: dialog plot: use full available height to display layers list.

Pcbnew: remove duplicate definitions of some flags (like EDIT and IN_EDIT) that have exactly the same meaning, but different values... (very dangerous)
Remove obsolete code.

* Rename all member variables and methods that reference the cross hair
  code in draw panel object from cursor to cross hair to eliminate confusion
  between the two concepts.
* Rename cursor capture call backs in draw panel object to improve code
  readability.
* Create helper class for turning off the cross hair while drawing.
* Remove redundant block clear code.
* Remove redundant mouse capture call back reset code when end capture
  call back is called.
* Remove unused function definitions in base draw frame object.
* Lots of minor coding policy and doxygen comment fixes.

* Remove base screen methods from draw frame object and correct current
  screen methods in derived objects.
* Move restore old wires function code into schematic screen object.
* Make add junction method use current screen position instead of store
  position.
* Move poly line ghosting function into the delete current segment method
  as that was the only place is was being used.
* Add method to base schematic object of testing if object has a label
  that can be incremented.
* Simplified the schematic hierarchy traversing code.
* PCBNew Doxygen warning fixes.

* Remove all occurrences if #ifdef USE_WX_ZOOM and all associated code within
  the #else/#endif block ( old zoom code ).
* Removed the build option for USE_WX_ZOOM from CMakeList.txt and config.h.in.
* Removed all scaling code in base screen object.
* Fixed buffered paint and buffered client DC on Windows.  Buffering works
  properly on Linux and Windows.
* Modified kicad_device_context.h to automatically uses buffering on platforms
  where double buffering is supported natively.
* Remove all of the scaled versions of the drawing functions in gr_basic.cpp
  and any support code.
* Removed all traces of ActiveScreen global variable from eeschema and
  gerbview.
* Renamed Recadre_Trace to RedrawScreen in draw frame object.
* Renamed PostDirtyRect to RefreshDrawingRect in draw panel object.
* Lots of code cleaning an Doxygen comment improvements.