* build to "Debug" or "Release" temp directory
  * put linker turds (.lib and .exp files) in the build temp directory
  * tack on "_d" to extensions built with debugging
  * added 'get_ext_libname()' help in putting linker turds to temp dir
Also, moved the code that simplifies None to empty list for a bunch
  of options to 'finalize_options()' instead of 'run()'.