Ajax calls for "files" and "files_trashbin" apps

Frontend:
- The files app list now uses ajax calls to refresh the list.
- Added support the browser back button (history API).
- Added mask + spinner while loading file list

Backend:
- Added utility function in core JS for parsing query strings.
- Moved file list + breadcrumb template data code to helper
  functions
- Fixed some file paths in trashbin app to be similar to the files app
fixing no-repeat for IE8
calling replaceSVG() to display breadcrumb images correctly on IE8
fixing breadcrumbs on ajax loading of files
update file summary on ajax file list load
Added missing "files" JS to files_trashbin module

The recent refactoring for the breadcrumb resizing relies on the "Files"
object which is in the "files" Javascript file.

This fix includes it here as well.
Fixed ajax support to also update the current dir permissions
Changed breadcrumb event handling to not use delegate

Using delegate might break apps that embed themselves in the files
container. When an app embeds itself and the user clicks a breadcrumb,
it will simply reload the whole browser page.
Fixed JS error in trashbin app
Fixed loading mask/spinner to stay fixed on scroll
Use hash part of URL for IE8 in files app

Before this fix, the URL wasn't updated in IE8 when navigating into
folders.

This fix makes use of the hash part of URLs to make this work in IE8,
since IE8 doesn't support the history API nor changing the URL without
redirecting.

From now, both the regular query URL "?dir=somedir" and "#?dir=somedir"
will work in both IE8 and non-IE8 browsers.

In IE8, query based URLs are automatically converted to hash URLs upon
page load. The conversion is done on the server side by redirecting the
user to the updated URL.

When loading a page directly using a hash URL in the form
"#?dir=somedir" in IE8, the server doesn't get the hash, so it will not
return any results in that case and rely on ajax to load the first page.
Fixed files_trashbin to also use hash URL part for IE8
Merge pull request #4501 from owncloud/ajaxfilelist

Ajax calls for "files" and "files_trashbin" apps