Merge with default (feature freeze for 0.9)

--HG--
branch : stable
Backed out changeset: a6930bfbd908

This changeset causes crashes. Needs to be re-examined.
frameencoder: removing assign qp inconsistencies which were triggered for unreferenced P frames

--HG--
branch : stable
Merge from stable
param: set aq strength to 0 in CQP
param: fix typo in if-check.