obsolete directories in src tree: mmalloc, iwidgets, blt

[Steve Ellcey]

> blt was used at one stage by sid.  You might like to check if that's
> still true.  We were using some of the specialised widgets in blt in
> some of the visual components.
> 
> Ben

Thanks for the pointer.  I sent email to the sid email list and got a
reply that removal of blt would be OK with them.

	http://sources.redhat.com/ml/sid/2006-q2/msg00001.html

Steve Ellcey
sje@cup.hp.com