This now pulls all data from official jQuery sources. Either their CDN
or their github account. Google tends to serve outdated or even broken
files :-(

Unfortunately there's no simple way to get the latest stable jQuery-UI
so for now the version has to be adjusted manually in the script.

':' is the field delimiter in the authplain flat text
conf/users.auth.php file, but it's also used as an internal delimiter
for the 'mediawiki' password hash format. Currently using this hash
format corrupts the file

This change escapes ':' as '\:' in any field in the users.auth.php
file, and any '\' as '\\'.

Also adds test cases for escaping modes.

This should be superseded by a proper rewrite of the media manager code

The edittable plugin broke uploading in IE8 (and maybe others) because
the Handsontable script adds a function to the Array prototype and the
uploading script did not properly check that.

This avoids treating double slashes as single line comments in CSS when
they are used in a filter or content string.

closes #638