p2p/discover: fix api issues caused by leveldb update

rlp: fix list bounds check overflow (found by go-fuzz)

p2p/discover: persistent node database

godeps: refresh leveldb, clean up stale dependencies

Conflicts:
	rpc/api.go

Whisper cleanup, part 3

The list size checking overflowed if the size information
for a value was bigger than the list. This is resolved by
always performing the check before reading.

Ref: https://github.com/Gustav-Simonsson/go-ethereum/commit/21c4c155ee68890a069654dcc5bc083a867f65cd

Remove old logger from RPC pkg

Add privkey loading to block tests

And output as quantity, not data