Started adding tests
Added more vim tests
Travis-related fixes:

- Added language key to .travis.yml
- Added install key to .travis.yml
- Removed ---
- Replaced tabs with spaces
Fixed various flake8 errors
Added mercurial tests
Exclude tests from packages
Made it work with python-3.2, added some documentation

Existing tests are passing with python-2.7, python-3.2 and python-3.3. Tests are 
currently unfinished though.

Fixes #271