Use email to retrieve characters

[maxluoXIII]

I don't really have the ability to debug #89 without access to the database, but my guess is that the new Github authentication method generates a new user id. Using the email account associated with the account should be able to retrieve the old characters.

I'm not very experienced with MongoDB, so this will likely cause inconsistent behavior with regards to #55. Google seems to make all emails lowercase but Github retains case sensitivity. If both are lowercase, the accounts will be linked, but otherwise will remain separate. I couldn't figure out how to do a case-insensitive query, so if this is an issue any tips would be appreciated.

@Mottokrosh Could you check to see if this would fix the issue? Like I said, I can't effectively debug without access to the database.

[Mottokrosh]

@maxluoXIII, send me an email at shout at mottokrosh dot com and I can hook you up with DB access.

[maxluoXIII]

I found a better solution after looking at the issue in the database