Clean up

Random INLINE annotations appear.
Distances module = duplicate work (LOL)
@instance CubeAction FlipUDSlice@ definition.
Cabal file cleanup
Unwrap vector representation of "endo" values.

The move tables are computed using @Coord@ only for the 6 generating
moves. The other moves should be obtained by iterated composition of
these vectors, which is much faster.
Rewrite en/decodeCV

Bijective mapping between integers and combinations

Use arrow combinators
Fix bug

Cube to UDSlice conversion was incorrect (confused replaced-by and
carried-to representations).
Reuse type synonym