- (dtucker) [Makefile regress/Makefile] Fix portability issues preventing

 - (dtucker) [Makefile regress/Makefile] Fix portability issues preventing
   the regression tests from running with Solaris' make.  Patch from Brian
   Poole (raj at cerias.purdue.edu).

Further info:  Solaris' /usr/ccs/bin/make
* requires a space before "+=" (but not "=")
* does not like @for

The bit that relies on a trailing "/" on $OBJ so "rm ${OBJ}$$F works in the
current dir if OBJ isn't set is my fault.  Nasty but it works.