Bumpv

- Fix: --parse/--serialize didn't work from cfg
([\34](https://github.com/peritus/bumpv/issues/34))

- Don't fail if git or hg is not installed (thanks keimlink)
- "files" option is now optional
([\16](https://github.com/peritus/bumpv/issues/16))
- Fix bug related to dirty work dir
([\28](https://github.com/peritus/bumpv/issues/28))

- Fix --tag default (thanks keimlink)

- add {now} and {utcnow} to context
- use correct file encoding writing to config file. NOTE: If you are
using Python2 and want to use UTF-8 encoded characters in your
config file, you need to update ConfigParser like using 'pip install
-U configparser'
- leave current\_version in config even if available from vcs tags
(was confusing)
- print own version number in usage
- allow bumping parts that contain non-numerics
- various fixes regarding file encoding

- bugfix: tag\_name and message in .bumpv.cfg didn't have an effect
([\9](https://github.com/peritus/bumpv/issues/9))

- add --tag-name option
- now works on Python 3.2, 3.3 and PyPy