* Removed unittest2 dependency on Python >2.6.
* Moved discover_tests.py into tests/.
* tokenizer.c: Fixed errors noted by -Wshorten-64-to-32.

- Add a _SliceNormalizerMixIn to properly handle slices.
- Use floor division when applying key.step.
- Implement sort() without 'cmp' parameter.
- Fix bytes(list) behavior.
- Children of _ListProxies are now _ListProxies, not regular lists.

- Skip CTokenizer tests if CTokenizer is not available.
- TestStringMixin: Don't make assumptions about default encoding.
- Add urllib stuff to mwparserfromhell.compat.
- Fix compat.py's line endings.
- gen.next() -> next(gen)
- assert*Equals() -> assert*Equal()

Add from __future__ import unicode_literals to a few files.