test(bitswap) enable get block test
chore(bitswap) rm unused helper func
refac(bitswap) nil slices are 'range'able
test(bitswap) add SessionGenerator
docs(bitswap:strat) interface comments
test(bitswap:testnet) shuffle the providers

to avoid letting client rely on order for correctness
feat(bitswap) ACTIVATE FULL CONCURRENCY cap'n

fix(bitswap) Put synchronously. Then notify async
test(bitswap) test with swarm of ~500 instances

test(bitswap) run synchronously to aid the scheduler