Firefox 14 build broken due to wrong libpng

[Dan Allen]

My build from ports of Firefox 14.0.1 dies in the configure script.  It says that the system PNG library does not support APNGs.  (I am on FreeBSD 8.3 stable.)  Anyway, if I manually run config

	./configure --without-system-png

then configure succeeds, but then configure says that I am not building with a separate obj tree and gmake ends up failing later on.  Obviously I need the full build scripts.

Possible fix: add --without-system-png to the BSD overrides?

Dan Allen