Cleanup ANF frontend some more

Eliminate the awkward old ANF language in favor of direct translation to
Cruxes in Dyna.Analysis.ANF.  Evaluation cruxes are now properly indexed
within rules using an Int, so we don't have to rely on the output variable
being unique.  There are more flavors of unification cruxes, including
inequality constraints.

The terrible 'handleConflictors' has been replaced with a much more
sane function which operates on cruxes, rather than on DOpAMine, which will
be welcome when we have more interesting OPIter modes.

While here, move python scripts from bin/ to src/Dyna/Backend/Python and
adjust the world.  Use this as an excuse to make ./debug invoke the dyna
compiler only once and dump everything to different files in $PROGRAM.d/