re-organized $auth providers

- moved providers for readibility
- made the provider getter/setter more flexible (with iterator)
- now, if no params are provided, it will also return current config
@stryju merge fixes and corrections
removed user_likes from facebook scope
formatting: popup options object on one-line
readme updates
readme: updated oauth1 and oauth2 instructions
readme: updated reference api
v0.6.0
removed unused $rootScope parameter
node: return 200 ok on unlink
Merge pull request #87 from chena/dw-rest

Dropwizard: signup and login
readme fixes and typo corrections
Merge remote-tracking branch 'origin/master'
readme: update
moved how it works into wiki
Working on unlink
Merge branch 'master' into dw-rest
Added error message in AuthFilter
Added Provider enum in User, show server error client side fore unlink
Implmented unlink, check log-in method counts, and refactored to use Provider enum