Version 1.3
Add support for the Google Application Default Credentials.
Require python 2.6 as a minimum version.
Update several API samples.
Finish splitting out oauth2client repo and update tests.
Various doc cleanup and bugfixes.
Two important notes:
* We've added `googleapiclient` as the primary suggested import
name, and kept `apiclient` as an alias, in order to have a more
appropriate import name. At some point, we will remove `apiclient`
as an alias.
* Due to an issue around in-place upgrades for Python packages,
it's not possible to do an upgrade from version 1.2 to 1.3. Instead,
setup.py attempts to detect this and prevents it. Simply remove
the previous version and reinstall to fix this.