Update jquery.ui Vector theme to 1.9.2

Follows-up 3cb2ccd87863abb8a99ed7d970730ae9e4138fcc.

Various structural changes were made in jQuery UI 1.9, and the Vector
theme was not updated to accommodate for those changes.

There have also been lots of small improvements to the base theme (which
is substituted inside the Vector theme) that were made over the past few
releases that weren't backported (such as Ib099282484b for bug 67243).

And there were two new modules in jQuery UI 1.9 (menu and spinner) that
were lacking Vector theme stylesheets.

Source files generated with http://jqueryui.com/themeroller by
downloading the theme for v1.9.2 (except for jquery.ui.button.css). See
the permalink in jquery.ui.theme.css.

For jquery.ui.button.css, use latest master of jQuery UI 1.11.2-alpha:
* https://github.com/jquery/jquery-ui/blob/8825d93dc8/themes/base/button.css

This is from a newer version of jQuery UI but user MarkTraceur suggested
the file for jquery.ui.button had fixes that were not backported to 1.9
and does not cause problems with Wikimedia Commons.

Documented our patches in a PATCHES file.

Change-Id: I2a31e4a3d969a966935a50392deafd756e2b9fca
Merge "Update jquery.ui Vector theme to 1.9.2"