Log Message:
We used to avoid building all of Subversion again when building
sub-packages (p5-subversion, py-subversion, and ap2-subversion) by
hand-hacking build-outputs.mk, which was a big pain.  Consequently,
since the 1.0.7 update, pkgsrc has re-built the whole thing for each
subpackage.  This is annoying and makes p5-subversion not work with
pkgviews on Darwin.

Now, we'll fix the problem by patching gen-make.py, which generates
build-outputs.mk.  I may even be able to commit this change upstream.

devel/subversion-base/Makefile:
    Generate build-outputs.mk hack.

devel/p5-subversion/Makefile:
devel/py-subversion/Makefile:
www/ap2-subversion/Makefile:
    Replace build-outputs.mk in post-patch.