Fixed pull request

Sorry for trouble with my previous pull request. I did not guess that files in src/emit/Caml/ are autogenerated and I messed up Ramana's commit.

I think that .gitignore entries for src/emit/{Caml,ML} can be modified to:
src/emit/ML/*.sig
src/emit/ML/*.sml
src/emit/Caml/*.ml
src/emit/Caml/*.mli