title: Debug vs Release in CMake
body: <p>In a GCC compiled project,</p>
  
  <ul>
  <li>How do I run CMake for each target type (debug/release)?</li>
  <li>How do I specify debug and release C/C++ flags using CMake?</li>
  <li>How do I express that the main executable will be compiled with <code>g++</code> and one nested library with <code>gcc</code>?</li>
  </ul>