Remove the Win32 script-processing exception from mod_cgi, and
   roll build_command_line/build_argv_list into a unified, overrideable
   ap_cgi_build_command optional function.

   Eliminates a ton of Win32 cruft from core.c for registry parsing.
   Win32 (through the default handler, and newest changes to the
   apr_proc_create fn) continues to serve .bat/.exe files.  This is in
   preparation for adding modules/arch/win32/mod_win32 for scripts.

   Please review the mod_cgi.c behavior very carefully.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91058 13f79535-47bb-0310-9956-ffa450edef68