(1) Add MASTER_SITE_AFTERSTEP and MASTER_SITE_WINDOWMAKER for the master

and mirror sites of two popular window manager suites.

Submitted by: Brian Handy <handy@lambic.physics.montana.edu>

(2) Upgrade for Motif-2.1.10. It requires libXpm and libXp now.

(3) PARALLEL_PACKAGE_BUILD will now ignore BROKEN.

(4) Add new variable PKG_IGNORE_DEPENDS to not register some ports as

dependencies.  Useful for stuff like XFree86 and Motif.

Reviewed by: jkh