Pcbnew: fix  Bug #1422093 (pcbnew crashes after editing a footprint cominng from the board  with the fp editor and saving it on a librray and trying to load it to the board)
Some other very minor fixes.

* Fix resource leak in idf_parser.cpp
* Fix logically dead code in idf_parser.cpp
* Fix use after free bug in idf_parser.cpp
* Fix unitialized scalar value in idf_parser.cpp
* Fix logically dead code in idf_outlines.cpp
* Fix unitialized scalar value in idf_outlines.cpp
* Fix invalid iterator in idf_common.cpp
* Fix unitialized scalar value in vrml_layer.cpp

* Fix unitialized variable in MSG_PANEL_ITEM default ctor.
* Fix a bunch of uncaught exception issues.
* Fix a memory leak in the NETLIST_READER::GetNetlistReader() when an
  an attempt to read an invalid net list file occurs.

* Add support for VRML DEF coordinate key word.
* Coding policy fixes by Blair Bonnett <blair.bonnett@gmail.com>
* Debugging output clean up.

This method is added for scripting purposes, to be able to query
specific board layer names thru a board object.

If no board specific layer name is found, it will fallback to
standard layer names.

Now OpenGL can report its problems instead of shutting down the application.

* Add test to CMakeLists.txt to verify wxPython is installed when
  KICAD_SCRIPTING_WXPYTHON=ON.
* Add test to make sure wxPython version major and minor numbers match
  the version of wxWidgets found.
* Add code to set the correct version of wxPython to the python scripting
  initialization code.
* Minor code simplification in Pcbnew KIFACE main window creation.

Rename eeschema/dialogs/dialog_sch_find.fbp to dialog_schematic_find_base.fbp, to be consistent with other dialogs. 
Pcbnew run from the project manager: add menu Save Copy As..., which is the same command as Save As ... in stand alone mode, but with the constraints of a project (no cwd change, no board filename change, and keep project settings)

Pcbnew: Fix Bug #1420074 (Crash when a footprint is added to the board (or edited) from the footprint editor, if a new pad was added, because the net info of the new pad is broken in this case)

Pcbnew: fix ver minor issues. ModEdit: fix issue in GAL mode: when importing a footprint from the footprint wizard, the new footprint was not shown.

Prevent Pcbnew edit graphics property dialog from excepting zero length objects.  (fixes lp:1392117)

Pcbnew: fix Bug #1418135 (scrollbars never shown in design rules dialog, in netclasses grid list, which prevent to use many netclasses). Also fix very minor other issues.

* Using a Web navigator embedded in Kicad can create security issues in Kicad.
* The web kit is not always easily available on Linux.
* There is now a tool in kicad fp lib wizard  to list and select the .pretty libs available on Github Kicad repo (When the kicad plugin is selected, this tool can download and make a local copy of these libs)
However, using -D KICAD_USE_WEBKIT=ON when invoking  cmake still build the embedded web viewer.

Pcbnew - plot dialog: fix Bug #1417435 (Gerber(and some others)  plot mode is fixed as”sketch” instead of "filled" )

Dialogs edit footprint in module editor and edit footprint in board editor: add button to edit the selected 3D shape filename.
Dialog edit component in library editor: add button to edit the selected footprint filter.

Dialogs edit footprint in module editor and edit footprint in board editor: add button to edit the selected 3D shape filename.
Dialog edit component in library editor: add button to edit the selected footprint filter.

Pcbnew: simplify draw code in  default canvas and plot functions by removing the plot LINE option, which is not existing in all plotters, not existing in opengl/cairo canvas, and not usefull in default canvas.

ModEdit: add a settings menu option(and the corresponding dialog) to set default values used when creating a footprint or add graphic items to a footprint being edited.
These settings are now not common to the board editor, because the footprint editor can be run outside the board editor.
download_boost.cmake: ignore  .htm* files when installing boost. They are not used, and often have a very very long (and stupid) name which sometimes creates issues.

Class BOARD: Rename an overloaded method named SetLayer with the better name SetLayerDescr, and comment it. It also remove some warnings when compiled with option -Woverloaded-virtual

* Fix -Woverloaded-virtual warning in DIALOG_LIB_NEW_COMPONENT class
  definition.
* Make EDA_ITEM::Matches( const wxString& wxFindReplaceData& ) protected
  since it's a helper function that should only be called by derived objects.

Footprint Editor: New footprint creation: change defaults for ref and value texts: now Ref text is REF** and Value text  is the footprint name. Also Value is put on fab layer (front)
muonde.cpp: cleanup this very old code, and fix not working code.

* Check to see if image handler is already initialized to prevent warning
  on debug builds.
* Change LIB_PART destructor message output to use wxLogDebug for debugging
  on windows builds.
* Minor code cleaning and coding policy fixes.