Edited readme.markdown via GitHub

Updated to match sample in official Tropo repo.

(Fix) Corrected issue with Ask method, not setting terminator on Choice properly.

Added ability to set On Object to Transfer

Added Tropo REST API classes, and provisioning samples.

Added TropoClasses.php file for backward compatibility

Changing name of Tropo class file.

(Fix) Corrected bugs in createSession() method.

(Fix) missing second argument on property_exists in Result and Session

(Fix) sample code in readme contains some incorrect case

(New) Tropo::createSession() method for launching tokens

(Change) Avoid PHP errors if Result or Session objects are created and no json (or incorrect json) is present

(New) Add voice as a global parameter on Ask object

(Fix) Tropo::say() calls Say class with incorrect number of parameters.

(Fix) Choices object has incorrect name for terminator