Fix CURRENCY alignment.
A function with a [retval] param has a bit set in the FKCCIC bitfield.
Two functions with the same name share the same id.
The param names of propput and propputref functions don't go into the
typelib.
unless the inherited interface doesn't itself inherit.
Fix the id, sizevft and datatype2 fields for interfaces that inherit.
Prevent a crash if the typelib is empty.
Clarify a few more entries on typelib_struct.h