Add Integer trait type.
Add a couple of extra tests.
Add C-level fast validator.
FIX: PyLong_AsLongAndOverflow doesn't exist before Python 2.7; use PyLong_AsLong instead.
Merge remote-tracking branch 'origin/master' into feature/integer-trait-type
Replace existing Int with the new Integer.
Remove mentions of  from the docs.
Revert unecessary whitespace change in docs.
Make compatible with Python 3.
Merge pull request #104 from enthought/feature/integer-trait-type

Add Integer trait type.