apr-util buildconf copying rules.mk from ../apr

[Jeff Trawick]

It is helpful to be able to run buildconf prior to building APR. That 
won't work anymore (ain't no ../apr/build/rules.mk prior to building APR).

This breaks Apache, which has buildconf that first runs apr buildconf 
then apr-util buildconf.

I thought the point of grabbing apr's rules.mk was to be able to build 
apr-util from a pre-installed apr.