jquery source cleanup

jquery source cleanup

* Add unminified jquery js and css files to source.
* Update to jquery 1.6.2, and jquery-ui 1.8.14.

The full files are included in the source but not the binary.

I'm not minifying the files as part of build because I don't want ikiwiki
to build depend on a javascript minifier. (Let alone need one at runtime).
Nor do I want to deal with any breakage caused by the minifier. These
files were taken from the debian packages.

The jquery-tmpl full file was taken from revision
66bb852217c49ae8c9a8f2522150354ae80463de of its git repository, which
matches the minified file I already had. I did not want to deal with possible
breakage in newer versions; this thing claims to need an ancient version of
jquery (1.4.2), and is perhaps only working by luck with the newer versions
as it is.