Adding multiple arguments support for FB.ui and FB.api

I've added support for multiple parameters for FB.ui and FB.api

According to documentation:
https://developers.facebook.com/docs/reference/javascript/FB.api/
https://developers.facebook.com/docs/unity/reference/3/FB.UI/

both FB.api and FB.ui take more than one parameter, but last one is always callback. So I proxy all parameters specified by user of $facebook object and add callback as last one.

All unit tests are passing. I slightly modified two of those to assure that we are not checking only first param scenario.