Use third-party API's instead of filestorage.dvcs_wrapper.py

[ksurya]

The repository interfaces is basically done using scipy_central.filestorage.dvcs_wrapper which uses command line interfaces.

This interface can be easily replaced with external (3rd party) libraries which are quite good that of we have.

1. https://bitbucket.org/haard/hgapi
2. http://mercurial.selenic.com/wiki/MercurialApi
3. http://pythonhosted.org/GitPython/0.3.2/

[3] Git provides much pretty good API to that of Hg. Since our current deployment has only very few packages stored, I think we can easily move to Git and use the API mentioned above.

(New libraries are to be updated here)