Thrift-1340: Add support of ARC to Objective-C

Client: Objective-c
Patch: Hirano Satoshi

Adds -objc-arc flag to compiler and if used removes the retain/release/autorelease from generated code



git-svn-id: https://svn.apache.org/repos/asf/thrift/trunk@1210732 13f79535-47bb-0310-9956-ffa450edef68