anchor.diff:  This way, simply running 'cl' will invoke the script instead of the real
   compiler.
   
  -Installation For Visual Studio
  -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  +Installation for Visual Studio
  +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   
   Some users have reported (see e.g. GitHub issue #18) that in order to make Visual Studio pick up `clcache`, the original compiler binary needs to be moved out of the
   way and replaced with the executable generated via the `py2exe` script:
  
positive.code: ~~~~~~~~~~~~
  
  Python 3.3+ is required.
  
  You can generate a self-contained 'clcache.exe' file using
  http://www.pyinstaller.org[PyInstaller]. If you don't have it already,
  
negative.code: 2. Rename `cl.exe.config` to e.g. `cl_original.exe.config`
  3. Copy `clcache.exe` to `cl.exe`
  4. Set `CLCACHE_CL` environment variable to point to `cl_original.exe`.
  
  Alternative installation via clcache.bat
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  
  This method is especially handy when there are multiple Python installations
  on a system.
  
  Create a clcache.bat and put it in a directory in PATH (e.g. %HOME%\bin):
  
      @echo off
      @setlocal
      rem this is a good place for clcache environment variables
      set CLCACHE_HARDLINK=1
      C:\Python35\python.exe C:\clcache\clcache.py %*
  
  Now set your compiler to `clcache.bat` in the build system, e.g. for cmake
  
      set CC=clcache.bat
      set CXX=clcache.bat
      cmake ...
      nmake
  
  Check stats via `clcache.bat -s`, clear cache `clcache.bat -C` and so on.
  
  Options
  ~~~~~~~
  