Add Facebook's Thrift Cpp2 Support

N/A

* add a new target fbthrift_library to support facebook's new
  async server/client: https://github.com/facebook/fbthrift

Change-Id: Ib286eec7ebb4998ac1825e8009229c0368afb37e
Signed-off-by: liuhuahang <liuhuahang@zerus.co>
generate cob_style interfaces

N/A

Change-Id: I784fc069626b7959dc79d34a34c405a8dda2239e
Signed-off-by: liuhuahang <liuhuahang@zerus.co>
Merge pull request #107 from huahang/master

Add Facebook's Thrift Cpp2 Support