Fixes a bug where if one tries to delete a file, then clicks undo, and then tries to delete the file again, no questions or undo options were presented.

Essentially, just set FileLists.lastAction = null when one clicks undo.

LDAP: permanantly watch group members. Emit post_addToGroup resp. post_removeFromGroup on membership changes, so that Sharing App can take care of files shared within the groups. Requires and relies on background jobs.

You have to put a presentation file that contains the presentation defined in html into your ownCloud with the file extension .impress
Then you can use this app to play it. It also contains a demo presentation that you can use to learn.
Help is welcome to improve this app. :-)

Conflicts:
	apps/contacts/lib/vcard.php
	apps/files/index.php
	lib/files.php

Refactor again so we can tell what item is being reshared in case the same source shows up. This is the end of the share_api branch, moving to master.

Large refactoring to allow for the same item to be shared to a group and again with a user in the group with different permissions