* cmd, consensus, eth: split ethash related config to it own
* eth, consensus: minor polish
* eth, consenus, console: compress pow testing config field to single one
* consensus, eth: document pow mode
This PR implements the new LES protocol version extensions:
* new and more efficient Merkle proofs reply format (when replying to
a multiple Merkle proofs request, we just send a single set of trie
nodes containing all necessary nodes)
* BBT (BloomBitsTrie) works similarly to the existing CHT and contains
the bloombits search data to speed up log searches
* GetTxStatusMsg returns the inclusion position or the
pending/queued/unknown state of a transaction referenced by hash
* an optional signature of new block data (number/hash/td) can be
included in AnnounceMsg to provide an option for "very light
clients" (mobile/embedded devices) to skip expensive Ethash check
and accept multiple signatures of somewhat trusted servers (still a
lot better than trusting a single server completely and retrieving
everything through RPC). The new client mode is not implemented in
this PR, just the protocol extension.
* core: reduce txpool event loop goroutines and sync structs
* cmd, core, eth: journal local transactions to disk
* core: journal replacement pending transactions too
* core: separate transaction journal from pool
* core: remove redundant storage of transactions and receipts
* core, eth, internal: new transaction schema usage polishes
* eth: implement upgrade mechanism for db deduplication
* core, eth: drop old sequential key db upgrader
* eth: close last iterator on successful db upgrage
* core: prefix the lookup entries to make their purpose clearer
Currently http cors and websocket origins are a comma separated string in the
config object. These are replaced with string arrays that are more expressive in
case of a config file.
