Include minified versions of JS plugins.

Included minified version from plugin repository if supllied there.
If not, used http://marijnhaverbeke.nl/uglifyjs on the unminified
source file (keeping "head" comments, which usually include license
info).

Saved ~42% of plugins.js. \o/

References #189
Re-minified jquery.tabs.js.

For some reason, the minified version supplied by the plugin's
repository threw an errow, so I reminified it with UglifyJS.

References #189
Merge branch '2.0' of github.com:s9y/Serendipity into 2.0