[project @ 2002-01-30 12:17:21 by simonmar]

Clean up this Makefile:

  - Use the enhanced automatic source-finding machinery from
    paths.mk rather than rolling our own,

  - Turn on UseGhcForCc to get our C files compiled with GHC.
    This fixes some obscure bugs caused by the fact that we
    were re-initializing $(CC_OPTS) in this Makefile using
    :=, when it had previously already been set with = (apparently
    different versions of GNU make behave differently presented
    with this kind of mixed assigment).