Respect closed registration setting in googleauth module

Users that don't already exist in the system will not be allowed
to create one by logging in with their google account.
Allow users to be created without a password, to support inviting users via OAuth
Fix failing style test
Merge pull request #28 from midasplatform/googleauth-invitation

Googleauth invitation
Fix display of disk space when necessary functions are disabled
Fix warning on querying module.ini files for certain filesystem types
Remove redundant config controllers
Add back button to some config pages
Fix dashboard using wrong data directory
Add more time zones
Tweak memcached settings
Apache 2.4 and PHP FPM support
Replace short PHP tags
Add missing SQL implementations
Add sample configuration for task scheduler module on App Engine
Various utility component fixes
Refactor and fix the writing of config files
Fix failing tests
Replace rand() with mt_rand()
Add App Engine email support