* Valve220: Project {axial, ortho, cam, from face} functions
* conversions between AP, BP and Valve220 brush types; conversions to Brush Primitives and Valve220 formats are lossless
* detect brush format and automatically convert to current one on map Import and Paste
* Valve220: fixed Reset function, implemented Rotate one
* Valve220: fix overwriting basis on brush clone/map import ( in Face( Face ) constructor )
* BP: fix: normalize shift values during import, arbitrary projections and face->fit
* Valve220: fix texture lock for scaling, fix for negative texdef.scale
* brush format is preference for [maptypes, brushtypes]: [mapq1, quake], [mapq2, quake2], [mapq3, quake3]:
preferences->Brush->Brush type: Axial projection, Brush primitives, Valve 220
* autodetect brush type on map opening
* brush face surfaceflags are optional on loading for flexibility
* 'Snap planes to integer grid' option is always off by default
