Basic work for right sidebar

Use the new IteratorDirectory instead of the fakedir wrapper

Fix removal of share permissions when share disabled for user

Make sure to hide empty content message when mask is shown

Add \OCP\ISession to AppFramework

Do not allow invalid default expire days

Store storage availability in database

Adding header support to class OC_OCS_Result

Also change style.

For a predictive behaviour we need to determine who is allowed to call render
methods on the views. Either, the main view is solely allowed to call render
and views do not do anything about output until then. Or, the main view relies
on the concrete views to be ready when things are about to be shown. The latter
approach has the advantage that concrete views know when they have to update
themselves (e.g. new data arrives or information change), but the main view
has now idea of the inner workings.

Sidebar scrolls with contents
Highlight currently show file

Sidebar now works in all file list views.
Moved owner to share tab.

Added owner info.
Added animation, but causes scrollbal.
Default file action now when clicking on name directly.
Fixed icon.
Added empty share tab.

Adds right sidebar with registrable panels (still WIP)

use the main search box to filter users in user management

Add Backbone.js

handle rmdir on files for ftp storages