offer TExtendedBinaryProtocol for customers

Sometimes, customers wanna put some options (whatever customers want) in each request and response. And these options ought to be transparent for applications.

Unfortunately, thrift protocol does not have good extensibility for extra functionalities. I would like to propose the following solution to address this issue.

1. TMessage adds a new field called "options"
2. customers set "options"
3. TExtendedBinaryProtocol writes "options" when "writeMessageBegin" invoked
4. TExtendedBinaryProtocol reads "options" when "readMessageBegin" invoked