Update UI libraries and lots of small stuff

Ok, this is going it be another fun one. Please test thoroughly as changing so much is going to break stuff, thanks.

What has been done:
  - #199: updated jQuery, jQuery UI, Bootstrap and used plugins. Replaced combobox plugin.
  - #109: fixed
  - #206: fixed
  - #208: fixed
  - #207: fixed
  - #186: fixed
  - #143: fixed
  - #110: fixed
  - #67: fixed
  - #211: fixed

Hope not too much is still broken :)