<Someone> noticed that if one builds something in util and the required .o
files aren't already built in src, the .o gets placed in the wrong place.
Added the missing '-o $@' to the compilation command.
- Pat noticed that makedefs -z makes both vis_tab.[ch], but they could be
built by two makes via make -j, causing corruption
- make -j at top level failed for similar reasons, added several
dependencies to ensure a valid ordering
- these changes will cause extra things to be built if you "make"
individual targets at the top level, but have little effect it you're a
real power user and "make" the actual target in the right directory
