AddNextHoles also adds prev holes
AddNextHole/PrevHole
Revert "memoLoadInfer: Type is now StateT+MaybeT+CT"

This reverts commit a9a218bd8d41262d6123e1b2b45bfbc44bce7e61.

Conflicts:
	Lamdu/Sugar/Convert/Hole.hs
	Lamdu/Sugar/Convert/Infer.hs