Makefile fix and hoaf<->haof

The top makefile has a little bug hidden under the counter. I fixed it.

Look in the manual for gmake. Usually all flags and variables not set in the makefile itself dynamically are exported to sub-make processes anyway. (You can make them exported, too)

MAKEFLAGS is not need if you use $(MAKE), but if you use it in other lines, be aware that it only contains the letters of the flags, not the "-" to make it recognised as a flag.

HAOF: Hypermail Archive Overview File:
The name is of course tonge-in-cheek, but it should be consistent. For whatever reason I also mix it up with hoaf, too. Okay, let's go with haof. Apply the patch and rename the contrib directory, please. :)

Bug-Hunter-Bernhard