title: How to tell CMake to use relative paths
body: <p>If I make my project I can see this: </p>
  
  <pre><code>[ 50%] Building C object CMakeFiles/hello.dir/hello.c.obj
  /cygdrive/c/users/me/Home/bin/iccarm  /cygdrive/c/users/me/Home/sandbox/iar/hello.c  -I/cygdrive/c/users/me/Home/sandbox/iar/foo -I/cygdrive/c/users/me/Home/inc   -o CMakeFiles/hello.dir/hello.c.obj
  </code></pre>
  
  <p>Since I always call <code>make</code> inside my <code>build</code> directory, why not using relative path for the sake of readability and compatibility across operating systems?</p>
  
  <pre><code>[ 50%] Building C object CMakeFiles/hello.dir/hello.c.obj
  iccarm  hello.c -Ifoo -Iinc -o CMakeFiles/hello.dir/hello.c.obj
  </code></pre>
  
  <p>Is it much better isn't it?</p>
  
  <p>Is there a way to force CMake to use relative paths as much as possible?</p>