* Check user write permissions before saving project, board, and footprint
  library files.
* Append read only to file name and path in title bar when the user
  does not have write privileges.
* Rename class WinEDA_ModuleEditFrame to FOOTPRINT_EDIT_FRAME.
* Lot's of Doxygen comment and coding style policy fixes.

Store the name of modedit active(/current/working?) library in a static variable. Edit some modedit strings.

* Make EDA_DRAW_FRAME current tool ID member variable private.
* Added global no tool selected ID to replace application specific no
  tool selected IDs.
* Change SetToolID to prevent setting the tool ID to anything less than
  the new global no tool selected ID and assert on debug builds.
* Change command and update user interface command event handlers to use
  new global no tool selected ID.
* Fixed schematic library editor add pin hot key handler.

* 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.

minor code cleaning. fixed minor warnings in debug mode.

Pcbnew:   Added grid origin patch from Lorenzo Marcantonio.   Converted set grid dialog from DialogBlocks to wxFormBuilder,  and added in this dialog the grid origin parameters settings.

inches and mm, the industry is crazy enough to force us with mixed
design. For example I routinely use imperial units for track size and
clearance, but drilling is strictly a metric issue...

So I added a little parser to recognize a suffix specification in the
unit text boxes... so you can put in things like:
1in (1 inch)
1" (idem)
25th (25 thou)
25mi (25 mils, the same)
6mm (6 mm, obviously)

The rules are: spaces between the number and the unit are accepted, only
the first two letters are significant.

As a bonus, it also recognize the period (.) as a decimal point
substituting it with the correct locale character (there was a wishlist
for it, IIRC). Most useful for number pad fans :D 

* Implement code to allow wxDC to handle coordinate conversions between
  device and drawing units.
* Add build settings to enable wxGCDC for wxGraphicsContext testing.
* Remove wxAUI conditional build cruft as it is now required to build
  Kicad.
* Fix scroll increment size regression to prevent jumping around the
  zoom center position.
* Add find GDI+ cmake module for building on WXMSW when wxGraphicsContext
  is enabled.

Code cleaning.
Patch for 3D problem with macOSX

* Complete comment translation of PCBNew source.
* Some tooltip capitalization fixes in PCBNew toolbars.

others minor bugs fix.

See also changelog

* Create single event handler for grid size events.
* Fix all frame windows to use new grid size event handler.
* Use offset relative to ID instead of ComboBox index to save last grid size.
* Move last grid size load/save setting into WinEDA_DrawFrame.
* Add equality and assignment operators the GRID_TYPE.
* Add current grid helper methods to BASE_SCREEN.
* Add GetPins helper to LIB_COMPONENT to replace GetNextPin where applicable.
* Add AppendMsgPanel helper to WinEDA_DrawFrame.
* Improve rounding for display of coordinates when millimeter units are selected.

* Split out application specific command IDs to prevent unnecessary rebuilding.
* Eliminate duplicate menu and tool bar command IDs.
* Split component library editor and viewer definitions to separate header files.
* More component library and document file merge code.
* A bunch of minor string readability and consistency fixes.

pcbnew: remove old of two To_User_Unit(), redraw ratsnest on/off, magnetic cursor to start move/drag module

Global variable unobfuscation, new library path search, and lots of other changes.  See CHANGELOG.txt.