title: How to add a custom build type to cmake?
body: <p>I want to add my build type to cmake to call cmake like this:</p>
  
  <p><code>cmake -DCMAKE_BUILD_TYPE=mytype</code></p>
  
  <p>I've written strings to my CMakeLists.txt:</p>
  
  <p><code>set(CMAKE_CXX_FLAGS_DEBUG "-fPIC -o0 -g")
  set(CMAKE_CXX_FLAGS_MYTYPE "-fPIC -o0 -g -m32)
  set(CMAKE_CXX_FLAGS_RELEASE "-fPIC -o3)</code></p>
  
  <p>But cmake uses compiler flags which were wrote in <code>CMAKE_CXX_FLAGS_DEBUG</code>.</p>
  
  <p>What I should do to add my build type correctly?</p>