Added addTranslations and fixed de.js file

Fixed de.js to use OC.L10N.register() and use to correct expected
format.

Added JS unit tests for OC.L10N class

Include translations JS script for all apps

- Added setup checks in JavaScript
- Moved isWebDAVWorking to JS using SetupChecks
- Moved internet connection checks to an ajax call that goes through the
  server

Path will only be shown if in subdirectory, not in root.

Updating Usages

Removing unused method

Adding JS Doc

Now using a natural sort algorithm that is more consistent between JS
and PHP (although not perfect in some corner cases)

- added OC.Util.naturalSortComparator that uses the same algo that was
  used for the user list
- changed user list and files list to use OC.Util.naturalSortComparator
- removed toLowerCase() and changed the comparator to use
  String.localeCompare()
- added unit tests
- added OC_NaturalSort that is used by OCP\Util::naturalSortCompare()

When using big session timeout values, the interval value might
overflow and cause the setInterval() call to ping the server in a loop
without any delay.

This fix adds a maximum ping interval of 24 hours.

Forward port of 00ec5fc1935c946e846a8ff28491e5b5b017b3d7 from stable6.

Snapper doesn't work at all for IE8 and IE9 and messes up with the main
container layout when enabled.

This commits disables snapper for these browsers.

Now that the navigation menu is always togglable, the media query
dependent code can be removed.

* added parameters for humanFileSize to trigger that behaviour
* add unit tests for that

Sometimes no icon file is passed to replaceSVGIcon(), it showed an error
in IE8 and broke the code flow.

This fix adds a check whether the file name is set.

- added sharing overview entries in the sidebar
- use OCS Share API to get the list of files