Add Gmail features

[dav-s]

With the new Gmail api released, it might not be too hard to implement Gmail as a service.

Sending an email could be similar to using post with the Blogger service, except the user would specify a recipient.

Getting emails would be a list, I suppose.

[vinitkumar]

We use gdata for accessing google APIs for other services. But I am sure this is pretty much doable. Thanks for the suggestion.

[vinitkumar]

For my own reference. http://stackoverflow.com/questions/10147455/trying-to-send-email-gmail-as-mail-provider-using-python

[vinitkumar]

@dav-s Will look into the possibility of this during the rewrite. Maybe in the later versions when a solid alpha version of it works. Closing it in favour of #274 to keep things clean. But making a note for this in #274 as well