FIX MappedTest is now running

Two fixes were necessary:
1) in `settattr_trait`, the call to `post_setattr` always returns None,
   and so the it does not equal zero in the conditional statement after
   that.

2) in `validate_trait_map`, `value in type_info[1]` raises an exception
   if `value` is not hashable

144 errors to go.