* Convert user interface guidelines to markdown and add to the documentation
created by Doxygen.
* Remove HOW_TO_CONTRIBUTE.txt. This information is covered elsewhere.
* Remove wxWidgets_patch_notes.txt.
* Add compiling.md with most of the important information from the plain
text versions of platform specific compiling files.
* Remove the old plain text compiling files and folder.
- Create KiCad road map document.
- Add road map to developer's documentation.
- A separate road map build command to CMake so the road map can be built
separately for use in websites.
- Update .bzrignore to ignore road map files generated by Doxygen.