Modifies inter/intra coding to allow all tx types

The nominal tx_type for a given mode is used as a context
to encode the actual tx_type for intra.

Results:
derflr: -0.241% BDRATE
hevcmr: -0.366% BDRATE

Change-Id: Icfe7b0a58d79bc6497a06e3441779afec6e01e21
18 files changed