chain: misc fixes.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
pool: emit `blocks` and `txs` event on pool.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
pool: when proxying peer->pool events. pass `peer` as the 2nd arg.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
peer: txs event - only emit hashes to mimic blocks event.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
0.12.1