Renamed models/sso.go to models/login.go
Added two new structs required to unmarshal the XML API response during the login process
Added LoadCorporationFromName to database.go
Added retrieval of information about a player's corporation via the EVE API to LoginSSOHandler
New corporations and players now get created in session's SetIdentity if they are missing
Moved SSO-related functions to separate file and out of LoginSSOHandler
(Login-process should be finished as of now)