#59 support for google apps

[Adam Ryczkowski]

I don't use gmail per se, but have emails processed by GoogleApps, which has the same features as gmail (and some more). I believe that to add support for it it will be enough to allow "@" in username, and if present, assume googleapps user. I believe that from calendar perspective GoogleApps has the same ports&api as gmail. At least user interface on http and way of configurig remote callendars in thunderbird lightning is exactly the same.

Adam