The public page now uses the public.php/webdav endpoint.

Also enabled more file operations like rename, move, delete and create
folder from the public page, which are now all possible thanks to the
public.php/webdav endpoint.

- Clicking a file row or selecting it will open the sidebar.
- When sidebar is open, its contents update with the last selection.
- Dragging doesn't open the sidebar but does update its contents if it was
open already.
- Switching folders closes the sidebar.
- Close sidebar when highlighted file got deleted/removed from list

* ref #12877

* removed the setDefault call because then it will always be
  reshown
  * was added with ba475d48
* fixes #18208

* getstoragestats.php returns now the owner and it's display name
* show proper storage stats notifications for shared folders

Since the thumbnail is now in a div, the code that tries to change the
thumbnail have been adapted here as well.

Added namespaces so that JSDoc can find them.
Fixed a few warnings.
Improved some comments.

When dropping files onto a read-only folder, a notification
is now shown instead of attempting to upload.

This for both the drag for upload and drag from inside the file list
cases.

Now binding properly with the file list instance object.

For some reason IE8 didn't like the sort function, so using the one from
underscore instead.

- fixed upload and storage statistics
- fixed infinite scroll to use the correct contain for scroll detection
- fixed unit test that sometimes fail for rename case
- controls are now sticky again
- fixed selection overlay to be aligned with the table
- fixed "select all" checkbox that had id conflicts
- fixed public page
- fixed global actions permissions detection
- fix when URL contains an invalid view id
- viewer mode now hides the sidebar (ex: text editor)
- added unit tests for trashbin
- clean up storage info in template (most is retrieved via ajax call now)

- FileList is now an instantiable class
- FileActions is now in namespace
- added App class for trashbin app
- moved trashbin overrides into classes extending FileList
- replaced many static calls with "this." or "self." to make the classes
  reusable/extendable
- new URL parameter "view" to specify which view is shown, for example
  "files" or "trashbin"
- added OC.Util.History utility class in core for handling history
- moved URL handling/routing to OCA.Files.App
- popstate will correctly update the current view and notify the view of
  the URL change so it can update the current dir
- added JS unitt tests for the trashbin app
- fixed public app to work with the new namespaces

- Added links to trashbin and shared dir
- Moved "WebDAV" settings block to the app nav's settings section
- Added sidebar support in trashbin app as well

Fixed drag and drop code to use FileList.getSelectedFiles() instead of
the visible DOM elements.

The file selection is now based on the internal model array
FileList.files instead of the visible checkboxes.

This makes it possible to virtually select files that haven't been
rendered yet (select all, then deselect a visible one)

Added more unit tests for selection (with shift and ctrl as well)

- moved file selection code to FileList
- fix selection summary when all files are selected
- nextPage now auto-selects files if "select all" checkbox is checked
- fixed trashbin to use the same selection logic as FileList

There is no need to use `showHTML` here.