code reorganization
add oauth2 factory
add oauth2 functions to buildUrl from querystring
addd popup object and facebook factory
add authenticate function
created addProvider method that replaces setProvider and hardcoded provider names such as facebook or google
requiredUrlParams is now an object instead of a function so it can easily be extended
fixed an issue where facebook's requiredUrlParams would override OAuth2 default params
removed third-party sdks
added providerLookup function
fixed popup baseurl
successfully obtained code via oauth2 facebook