param: correctly detect adaptive quant usage when checking --psnr
frameencoder: do not allocate noise reduction struct unless NR is enabled

This fixes output mismatch between asm / no-asm for 4:4:4 encodes.  Why? I am
not entirely sure yet, but this is an obvious bug fix.
psy-rdoq: eliminate dependency between psy-rd, psy-rdoq and rdoq.

RDOQ is turned on by default in rdLevels 4 and above. Psy-rdoq can be turned on
if rdoq is enabled at that preset. Psy-rd can be turned on with or without rdoq/
psy-rdoq.
Merge with stable
search: cleanup variable names and lossless comments
search: nit
Merge with stable
cleanup: remove reduce condition check
fix single thread encode issue