Adding back the main func to the curdling.__main__ module
PipSource is now able to use authenticated urls

The `-i` parameter now is able to process authenticated urls. You must
provide the credentials in the following format though:

   $ curdling -i http://user:passwd@server.com/simple <package>
Tests are now passing again
Fixing the dependency parsing using distlib (our new way to go)
Env.request_install() now receives the requester and data to forward to service.queue()
Removing unused code
New release: 0.1.5