Signed-off-by: Brice Maron <brice@bmaron.net>

security++

At the moment we only have a hint that a new version is avaiable and a link to a not yet existing page if updating information. This has to be improved.

Make OC_Connector_Sabre_File::get() return a PHP stream instead of the file content, as is recommended by SabreDAV to handle large files.

Added a jquery function to filter by attributes.
Add more logging in rename file
Use the new function to avoid errors

change the error hint from suggesting to change the owner of a directory to changing the permissions. changing the owner of a director is not possible via ftp.