Improving the way we select multilib packages for trees

[Joe Orton]

I've been fixing up my packages' -config scripts by just doing:

-libdir=@libdir@
+libdir=`pkg-config --variable=libdir $PACKAGE`

which is simple enough and a maintainable hack, and not entirely 
dreadful.

Still, I think this task is futile for many packages; httpd, mod_perl, 
probably both {postgre,my}sql.

joe