paths relative to ${.CURDIR} instead. Using BSDSRCDIR here means that it's impossible to compile these programs out of the source tree they're a part of, unless that sort tree happens to be the one at BSDSRCDIR.
move the include of bsd.prog.mk in front of the .PATH.
so we might as well use it. Lots simpler.
include <bsd.own.mk> if testing a MKxxx variable.