*) Implement "Copy On Write" (COW) support in GITHUB_PLUGIN.  See class header
   comment for GITHUB_PLUGIN which should flow into Doxygen output.
*) Rewrote: 
        PCB_BASE_FRAME::Save_Module_In_Library(): now uses fp-lib-table and PROPERTIES.  
        PCB_EDIT_FRAME::ArchiveModulesOnBoard(): now can archive to any writable library type.
        PCB_BASE_FRAME::SelectLibrary(): is now generic for selecting a library, not just the active library.
Ensure a unique FootprintEnumerate() return list in GITHUB_PLUGIN when using COW.
Pcbnew: Autoplace functions: renamed spread footprint functions. Rewritten.
Now footprints, after loaded by reading a netlist are grouped by sheets by the footprints spread function, and the grouping is better.
Rename 2 files. Fix minor issues. Clean code
FIX: Red Hat (and derivatives such as Fedora) support in kicad-install.sh
Pcbnew: fix Bug #1255568 (relative to .pos file creation). Minor compil warnings fixes
Better GITHUB class header documentation, better eeschema library field dialog stretching and title.
Even more clarification on "Github" plugin usage