And now use the new lookupLocation function to get the media path.

And now use the new lookupLocation function to get the media path.
With the added hack of prepending "suse/" I can now actually install a
package and it indeed downloads the right rpm.  I've only tried dry
mode, so no actual installation happens.  It seems as if installing just
one package doesn't really trigger a solver run, though (the
dependencies don't seem to be marked as to-install).

Due to the hack with the hard-coded datadir this only works when the
package comes from a susetags repo (the others don't yet have media
locations anyway).