Add authentication to all requests

[IQAndreas]

This allows the source to be a private repository.

Code already exists for these changes:

• asolkar/mkorenkov-tools@de4eff4
• daniel-liuzzi/tools@8220ff2

Also, why am I not using urllib2? Was there ever a good reason for that decision?

[IQAndreas]

Feature added in ba1c71a