Eeschema: fix a *very serious* bug in netlist generation: sometimes the netlist forgets pins for components having more than one part per package, in hierarchical designs.

Gerbview:   Added: read Excellon files created by Pcbnew. The full Excellon command set is not supported, but drill files created by Pcbnew are supported.

* 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.

gerbview: fix an issue when using layer list in toolbar to select layer (back to old layer under Linux)
Refresh screen when active layer is changed from the layer manager.

Gerbview: tweaking code: Now the active layer is drawn on top of other layers. This is an enhancement in stacked draw modes.

others: fix minor issues.

* 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.

* Move locate function code into schematic screen object.
* Move test for junction needed into schematic screen object.
* Move test for marking connected items into schematic screen object.
* Move delete item function code into schematic screen object.
* Move delete all markers code into schematic screen object.
* Add method for locating multiple items in schematic screen object.
* Fix minor bug in schematic field object hit test declaration.
* Initial encapsulation work on item picker object.
* Remove duplicate doxygen comments from item picker object source file.

All: fix a minor bur annoying issue: incorrect cursor shape after a block command (mainly when a tool is selected)

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

* Factor change schematic component orientation code out of switch statement
  into separate function.
* Remove redundant command events from schematic editor hot key handler.

* Change EDA_ITEM set flag function to set flag bits using logical or
  instead of assignment.
* Add clear flag function to EDA_ITEM to clear flag bit using inverted
  logical and.
* Factor change schematic text type code out of switch statement into
  a single function call.
* Schematic text orientation function renaming improvements.
* Lots of small coding policy changes to updated files.

All : modify macro FROM_UTF8, to ensure compatibility with files using a non utf8 encoding (old files created under Window, having some non ASCII characters).

* Factor component unit select handling out of huge switch statement into
  a separate function.

* 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.

Eeschema, Pcbnew: fix minor issues about mouse cursor position, when loading files or entering sheets.

Pcbnew: Better selection of corners and edges in zones. Usefull when selecting edge/corner by right clicking on a zone outline,  for hight density boards.