Add bookmarklet for zotero.org

I'll feel pretty dumb if this is already available (I didn't see it), but here goes. This is a bookmarklet that will generate barebone ODF/RDF marker for selected citations on zotero.org

The bookmarklet-mini.js is just bookmarklet.js passed through http://chriszarate.github.io/bookmarkleter/ but with !function(){...}() wrapper converted to (function(){...})(), which works better on Firefox.

Please double-check the item key that is created. I haven't tested it with actual ODF/RDF scan.