Adding support for export links to enable download on Google Docs files.
Fixed #13
Conforming to PEP8 Guidelines

EG. Use 4 spaces per indentation level.

http://www.python.org/dev/peps/pep-0008

All Python files checked with the pep8 tool:
https://pypi.python.org/pypi/pep8
Fixing indentation error.
Adding Trash and Delete methods

Adding the ability to trash and hard-delete files.
Added UnTrash method

Now you can bring things back from the trash.
Adding ServiceAuth method

This method is intended to be used when authenticating a service
account to use PyDrive.
Test for ServiceAuth method.