Fix to callback table.  Because it is realloced if the table is extended we must pass an index into the table rather than the address of an element.  Add a mutex for thread-safety.  Fix problems with Pascal calls.
Fix to callback table.  Because it is realloced if the table is extended we must pass an index into the table rather than the address of an element.  Add a mutex for thread-safety.  Fix problems with Pascal calls.

git-svn-id: 98787b36aaefbae4b30fa755be920954cd25e1e4@1380 ae7d391e-3f74-4a2b-a0db-a8776840fd2a

mn200/polyml,dcjm/polyml,mn200/polyml,polyml/polyml,polyml/polyml,mn200/polyml,dcjm/polyml,dcjm/polyml,mn200/polyml,polyml/polyml,dcjm/polyml,polyml/polyml