Fix minor bugs and typos and add some more debug output.
* Makefile (install-client-nokey): Create plugin-helpers directory and the mandos-client-iprouteadddel helper program. * initramfs-tools-hook (PLUGINHELPERDIR): Fix typo. * plugins.d/mandos-client.c: Change terminology; routes are "deleted", not "removed". All occurences changed. (add_remove_local_route): Renamed to "add_delete_local_route". All callers changed. Also pass "--debug" flag to helper if in debug mode. (add_local_route): Add debugging output. (remove_local_route): Renamed to "delete_local_route". All callers changed. Also pass "--debug" flag to helper if in debug mode. (start_mandos_communication): Add debug output when adding route.