Log Message:
sysMkPath should be ${PREFIX}/share/mk by default and only that.
Including e.g. /usr/share/mk results in sys.mk read from there
as well. On DragonFly this adds X11BASE and results in obscure
breakages. Since the mk files are supposed to be self-contained,
it doesn't make much sense to look in other directories anyway.
Bump revision to annotate this.

Discussed-with: reed@.
Reported-by: Aggelos Economopoulos <aoiko AT cc DOT ece DOT ntua DOT gr>