easier Rails mount, updates some stuff and uses newer driver and gems

* uses Dalli instead of memcache-client
** can run async if run in a reactor
* uses googlechart instead of gchart
* is now a stand alone rack app
** I found it easier to mount in rails projects with a custom prefix, atm I could not try out the instructions for Rack provided in the
* updated email
* bumps version

I'm not sure if you should merge it, because as I said it's not tested with Rack or Sinatra applications. However, I'd be interested in your opinion. Maybe you can cherry pick some of the changes.