Unify coding style of jQuery( '<element>' ) calls

According to jQuery and our MediaWiki style guide all kinds of
$( '<element>' )
$( '<element/>' )
$( '<element />' )
$( '<element></element>' )
are identical. So yes, all this patch does is removing characters
that are ignored anyway. Using the same style everywhere makes the
code easier to read and understand and may save a few bytes when it
is gzipped.

The current core/resources/ folder contains 148 jQuery calls of
that kind. Only this file (plus some jQuery plugins I don't want to
touch) do not use the most simple <element> style.

Plus:
* Added some line breaks.
* Fixed broken inline documentation.

Change-Id: I080716f21f2ab95164a9ca241a4ce4fc351e0b55