initial integration with iRODS www.irods.org
The used PHP API is hosted at https://code.renci.org/gf/project/irodsphp/
Merge branch 'master' into ext-fs-irods-master
in order to use the ownCloud login credentials we use a login hook to grab uid and password and store it in the session.
The stored credentials will be used for and interactions with the iRODS server.

Within the config UI a check box can be used to enable the credential reuse.
checkbox in settings ui
test case for iRODS storage added
Merge branch 'master' into ext-fs-irods-master
adding $backupGlobals = FALSE because iRODS is heavily using $GLOBALS
adding auth mode to ui and the url
Merge branch 'master' into ext-fs-irods-master
Switch to using Google Drive SDK, closes #2047
Setting Redirect URI is not required here
Prepare for #2013 fix
Fix constant in last commit
Include 3rdparty Google Drive SDK 0.6.2
Fix require_once for 3rdparty in google ajax frontend
Return null if file size is negative for WebDAV, fix #2013
Merge branch 'master' into googledrive
Merge branch 'master' into googledrive
Implement hasUpdated() to watch for changes on Google Drive side
substr storage id to prevent problems with storing the change id in appconfig