Drive: study the feasibility of using PycURL instead of urllib2 as the main HTTP library

One reason to use PycURL is that it can be used with Python 2.x to achieve SSL client certification, whereas it seems that urllib2 needs Python 3 to work well.
By default, Python 2.x with urllib2 will prompt for the password upon each request, which is unacceptable. Python 3.x allows the password to be captured externally and then passed to the underlying http library to open and subsequently pass the certificate to the server.

However, PycURL introduces a native dependency on libcurl so packaging for Windows / OS X needs to be validated.

PycURL might also be more performant as it uses a native library.