Added fast intra search option to Analysis::checkIntraInInter_rd0_4
analysis: use macro and for-loop to simplify fast-intra

this changes behavior a bit; it's trying both +/-1 offsets instead of just
one. and it has to do one extra check at the end since mode 34 isn't reached
by the other previous loops
param: don't allow turbo mode to increase rd-level, improve docs
quant: use optimized primitive for transquant bypass in invTransformNxN
analysis: avoid MSVC uninitialized variable warning