speedup TimerProfiler
move UpdatePieceMatrices() a level up
fix precision issue in SpringTime
fix a LLVM/Clang error in creg
atomic counter doesn't need to be volatile
(the used functions are memory barriers)
some bigger CMatrix44f changes
* switch to handcoded SSE1
 * Matrix * Vector: <10% _slower_ on AMDs on the other hand 10x faster on Intels
 * Matrix * Matrix: 30-50% faster for AMD & Intel
* switch Matrix multiplication order to math-standard one (not Directx one)
 * A = B * C = BC (and not `CB` as _before_!)
 * A <<= B; equals to A = A * B
 * A >>= B; equals to A = B * A
remove 2 near zero SCOPED_TIMERs
reduce code duplication