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

Mandatory in Pcbnew to handle without error metric grid used now for some footprints (BGA, connectors)
Not fully tested

Integrate wxFileHistory, add missing header files to fix Linux build, initial search path work, and general housekeeping.

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gerbview: add french translation, G55 command (a do nothing command) and solved a bug that can crashes gerbview with files without any DCODE tools info.

Improved grid implementation, 3D viewer debug assertion fix, moved drawpanel.cpp to common library, and added WinEDA_Appl declaration.