* path.c (exit_cygpath): Wait for subprocess to exit before returning.

* path.c (exit_cygpath): Wait for subprocess to exit before returning.
(cygpath_pipe): Don't call exit_cygpath.  Let main atexit routine do that.
* pkg.c (init_pkgs): Accept root argument.  Make registry key "cygwin
root"-specific.
* setup.c (filedel): Call exit_cygpath here so that we can be assured that
cygpath subprocess has died.  This allows us to delete cygpath.exe and
cygwin1.dll.
(optionprompt): Initialize response to -1 so that second screen of mirrors will
appear.
(get_pkg_stuff): Don't attempt to use HKCLU.  Pass root to init_pkgs.
* setup.h: Reflect init_pkgs prototype change.