Make limited reflection optional (off by default).

Limited reflection is deprecated, and it is slowing down compilation.
This change will disable generation of static reflection by default,
but it adds a command line argument to re-enable it.

Tested by running make check and building the C++ test client and server.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665520 13f79535-47bb-0310-9956-ffa450edef68