OSX build improvements.

* Compile all binaries into a single application bundle.
* Use CMake BundleUtilities to make application bundle relocatable.
* Restructure build output to directly create an image file.
* Fix default search paths.
* Set KIGITHUB environment variable.
* Added patch to fix wxWidgets so names for OSX.
Implemented TEXTE_MODULE::GetShownText

Handles % macro expansion in user texts inside pcb modules.
At the moment the following are available:
%%      A plain %
%R      Insert the reference
%V      Insert the value
Road map and Doxygen work.

* Remove obsolete settings from Doxygen configuration file.
* Fix some Doxygen warnings.
* Add the board edge segment snapping to developers road map.
* Fix some coding style issues in CMakeLists.txt
Eeschema: fix Bug #1376669 (graphics lost in aliased components)
Cleaning 3 svg files (no icon change)
Very minor other changes.
Use the alias name, not the root name, in the eeschema component chooser dialogue. Also show the name and the root component in the text area