QPID-5517: Provides a macro of add_compile_options

This is used IF the CMake version in use isn't providing the macro
already, which is the case in versions of CMake < 2.8.

git-svn-id: https://svn.apache.org/repos/asf/qpid/dispatch/trunk@1562933 13f79535-47bb-0310-9956-ffa450edef68