Locate the library and header directories for perl on Windows, just like how we handle them for ruby and python.
Locate the library and header directories for perl on Windows, just like how
we handle them for ruby and python.

* build/generator/gen_win.py
  (get_win_includes): Add perl includes if necessary.
  (get_win_lib_dirs): Add perl libdir if necessary.
  (_find_perl): Ask the required information from perl.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion