Update Dependencies Section

Git vcs module was done some time ago...
Remove ``--version`` option
Merge branch 'master' of https://github.com/kennyballou/Xnt
Refactor Versioning

Xnt now has a version module that all other modules shall use when requesting
version information
Add extension to README
Move version and dev status
Update One Line description
Update README build.py example
Update README

Add changes for 0.5.1