[Glesys] Bugs and new features added to glesys compute server model

There is several errors in the glesys compute server model like attributes that are present but they shouldn't and attributes missing. I've cleaned up the attributes to match Glesys API. Other changes include a `setup()` method is added to setup the server, a wrapper around  `ssh()` method to us the `rootpassword` attribute if available and a `public_ip_address()` method.

I would like to change the name on some attributes, is this viable? @geemus @antonlindstrom