Big minify update

Long story short: jsmin-php has become an abandoned, unmaintained project.  So, I've swapped it out for php-closure, which implements the Google Closure JS Compiler web service via REST API... which is much more efficient.

I also wrote a wrapper for it so we can call it easily from the command line, write directly to files, and (importantly) keep copyright headers.  I put these scripts in a new directory, so the next time we swap out minifiers we only have to modify one script.

Then, I fixed all existing scripts that used jsmin-php, then re-minimized them (well, all except uploadify, which will soon be obsolete).  Also, I updated the jQuery libs to be minimized.

Result: we're back to being current!