Reimplement Win32 registry-based and shebang-extended scripting.

  Accepts arguments of $* and %* for 'positioned' cgi envvars, provided they
  stand alone (aren't part of another arg.)

  Accepts %1 $1 syntax, quoted or not, but makes no attempt at palacating
  older programs with short paths, just yet.

  About as stable and robust as my first rewrite of dir_walk, so watch out!


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91613 13f79535-47bb-0310-9956-ffa450edef68