2.86
use clew/clew.h path
fix many warnings remove btMultiSapBroadphase.* make collisionFilterGroup/collisionFilterMark int (instead of short int)
move shaders to .glsl files and stringify to .h file. add crude screenshot facility (using F1 key), it can also be used for debugging start with shadows using shadowmap, not working yet add experimental 'ignore' body index in raycast, using b3HitInfo.m_m_hitResult2