QPID-5176: Simplify CMake specification now that we don't need to compile
  different files in qpidmessaging differently. This also avoids some Visual
  Studio 2008 breakage.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1528184 13f79535-47bb-0310-9956-ffa450edef68