Add a NatArray.Unsafe module.
WIP: adding handler pool to loops
Merge branch 'lvish-graph-algorithms' of github.com:iu-parfunc/lvars into lvish-graph-algorithms

Conflicts:
	haskell/lvish-graph-algorithms/lvish-graph-algorithms.cabal
	haskell/lvish-graph-algorithms/src/Data/Graph/Adjacency.hs