Initial impl of PurgeAll. Updated authentication.

Created UnitTest with mocked behavior for PurgeAll. Will create an
integration test next. Added the Google sample code to the _lib folder
for reference. Updated the authentication to use GDataCredentials
Created integration testing for PurgeAll events.

Created full integration testing for the CalendarPurge.PurgeAll method.
Minor clean up of existing unit tests for name conventions.