1) Unify metrics between stroke and outline fonts
2) Unify handling of rotation and mirroring
3) Bug fixes in collision handling
4) Use of VECTOR2I (instead of VECTOR2D) for world-coordinates
5) Generate outline font overbar with rounded ends and fix rotation
bugs
6) Generate wxEVT_CHOICE events from FONT_CHOICE::SetFontSelection
7) Change text-item PNS SOLIDs to use compound shapes
* Split up the thirdparty code into the thirdparty folder (#3637)
* Create a new kimath static library containing all the math functions
This is part of cleaning the build system for #1906.