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
Add classes replaced by the public api to the code checker
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