Add CONFIG_INTERINTRA flags and reduce # of interintra modes to 4

Use CONFIG_INTERINTRA to properly separate interintra from the basic
ext_inter experiment.
When macro REDUCE_INTERINTRA_MODES is 1, only 4 ii modes are enabled
so as to reduce the complexity overhead.
(Right now the flag is off)

Change-Id: Iec6f36a1000f181adbb822ad66c7d5b2625e9cc7
14 files changed