4129 ON tools should honor $MAKE
4130 cmd/refer Makefile is a bit bogus
4131 xref hardcodes its path
4132 ndmp makefiles need to use $(RPCGEN)
4133 Need a way to specify ast binary directory
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Cedric Blancher <cedric.blancher@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>