The previous code would emit a full set of state during the first EmitState on

The previous code would emit a full set of state during the first EmitState on
a new cmdbuf, to ensure that state wasn't lost across UNLOCK/LOCK pairs (in the
case of context switching).  This was rather inefficient.  Instead, after
flushing a cmdbuf, mark the state as needing to be saved on unlock.  Then, at
the beginning of flushing a cmdbuf, if we actually have lost the context, go
back and emit a new cmdbuf with the full set of state, before continuing with
the cmdbuf flush.  Provides a 10-15% improvement in ipers performance in my
tests, along with other apps.

Tested with:	ipers, glxgears, quake3