feat(blockstore): implement blockstore
style(blockstore) move to top-level
refac(bitswap) use blockstore
refac(bitswap): privatize bitswap
chore(util) rm unused DatastoreKey method
refac(bitswap) privatize strategies

temporarily. until bitswap is refactored
refac(bitswap) privatize ledger

temporarily. at least until refactor is complete
refac(bitswap) define Directory interface
Merge pull request #4 from jbenet/net

Net