title: CMake flag changes debug configuration
body: <p>I have a project running on CMake 2.8.9, and use Visual Studio 2008 for building. In the CMakeLists.txt I switch the default runtime library for debug configuration to MTd:</p>
  
  <pre><code>set(CMAKE_CXX_FLAGS_DEBUG "/MTd")
  </code></pre>
  
  <p>Unfortunately, this line also causes switching the flag "Debug Information Format" to "Disabled", which means that I can't debug my project. :-(</p>
  
  <p>If I remove the line from the CMakeLists.txt the runtime library is "MDd" and also the "Debug Information Format" is "Program Database (/Zi)". Does anybody know the reason or how to avoid the issue? Is there any workaround? Is it possible to set the missing flag via CMake?</p>