r9611: Reset global variables (hf and ett lists) for each parser run. This

r9611: Reset global variables (hf and ett lists) for each parser run.  This
avoids building up buckets of unecessary definitions from other parsers.

Get rid of warning and FIXME for unknown data types.  This is handled
by the interface depends list and including the appropriate header files.
(This used to be commit eb5e3b031cd18fb1f83d9ccbb21e5148c8c1cdd0)