Add a -C ala GNU make(1) for Makefiles which are too lazy to use $(MAKE) and

Add a -C ala GNU make(1) for Makefiles which are too lazy to use $(MAKE) and
this particular GNU flag.  It changes into the given directory for the
operation in question.  This just goes into said directory at the time of
parsing the argument for getopt(3).

Submitted by:	Rachel Hestilow <rachel@jerkcity.com>