enhance to use also new icons from WP 3.9

I have update the array of each icon to use also the new icons from the last WP version 3.9.
I use your picker in this plugin (https://github.com/bueltge/WordPress-Admin-Style), to find easier a icon for custom development.
The other changes on the plugin is only a version number and a little bid WP codex.

Best regards
Frank