Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 compilation_module(Arg1)

 compilation_module(Arg1, Arg2)

 compile_time_called(Arg1, Arg2, Arg3)

 compilation_predicate(Arg1)

 before(Arg1)

 after(Arg1)

 init_expansors