oauth1.exchangeForToken refactoring
#114 Aditional data to $auth.authenticate

Made possible that the $auth.authenticate function can receive a second parameter (Object) that will be passed all the way down the oauth request pipeline (either OAuth1 or OAuth2) to be sent the the server's final post.
ex. In a Facebook login, after the popup has closed, it will be object will be serialized along with the code, clientId and redirectUri and sent to the server
readme: fixed typo
readme: updated api reference
readme: fixed api reference url
readme: formatting updates
readme: added browser support and updated credits section
check if popup is open and popup.focus is defined before focusing
Implements basic architecture, and facebook authentication
reversed popup communication, no longer use postMessage
use ie-compatible window.location.origin for redirectUri
check if window.atob exists
readme: updated browser support
readme: updated table of contents
Merge remote-tracking branch 'origin/master'
readme: center align browser versions
inline redirectUri fallback to make it clear
readme: updated configuration
code cleanup
added loginOnSignup unit test