Replace httplib calls with python-request

The idea is to migrate all httplib calls into something based on python-requests[0].

Since python request already takes care of most of the things related to http requests, headers and different aspects around it (chunks, keep-alive, gizp, json, etc), it could be a good thing to migrate this, and other OS clients to use it.

Couple of more things about python-requests:

1) There's a well formed community around it.
2) It's continuously updated
3) If there's a bug / patch, that can be verified, it'll get in.
4) It's been packaged for Ubuntu, Debian, RHEL and Arch

Some benefits:

* It'll reduce the code that should be maintained
* Cleans up some of the existing code
* Heads clients to a more standard code base

Drawbacks:

* If we find a bug, even though we can contribute back, it'll take a bit more to have that fix pulled in.

This changes would be backward compatible and wont affect how the client works.

[0] http://docs.python-requests.org/en/latest/