update js folder

- add images from jquery-ui to css folder, the stylesheet expects them being around even though we don't use them, adding them and not using them is better then editing the stylesheet and then forgetting about it again after every jquery-ui update, i suppose..
- fix html5shiv name, it was minified to begin with
- bump flot to 0.8.3, fix plugin name (no functional changes for us)
- bump tablesorter to 2.16.4 (likewise)