Revert "Makefile.OCaml: fswatch.cmi depends on ubase/prefs.cmi."
Revert "Makefile.OCaml: fswatch.cmi depends on ubase/prefs.cmi."

This reverts commit 5ca514261da345e762bfe43f5ff6edb12364d814.

Make dependencies are kept in .depend

paulp/unison