Fix for Microsoft login

[LAK132]

Add a second username slot in the config file
eg:
"skype_username" : "asdf@live.com", //login username
"live_username" : "live:asdf_123", //username that is returned by messages or blank if not using Microsoft account

Compare the receiving username against both:

var spypeIsNotSender = (message.resources.from.toLowerCase().indexOf(config.skype_username.toLowerCase()) === -1) && (message.resources.from.toLowerCase().indexOf(config.live_username.toLowerCase()) === -1)

Viola, bot no longer replies to itself

[findel]

Hey! I don't think that I knew this was an issue.

If you would like to submit this as a pull request I would be happy to accept it.

(Sorry for the slow reply, email notifications seem to have not come through for issues here)

Thanks!