Basic library fixes

[holgerd77]

Would like to get the client library off the ground a bit again so that it gets at least ready for some experimentation and testing. I would directly merge these first PRs in for practical reasons until things settle a bit. Feel nevertheless free to comment.

This PR makes the library installable again by updating the level dependency and adds some explanation on how to run via CLI.

@PhilippLgh I tested this with the latest devp2p code by locally packing and installing, this is not syncing yet, would like to debug here first before we release on the devp2p side, output:

$ ethereumjs
INFO [05-20|23:52:48] Data directory: [PATH]/ethereumjs/chaindata
INFO [05-20|23:52:48] Initializing Ethereumjs client...
INFO [05-20|23:52:48] Fast sync mode
INFO [05-20|23:52:48] Connecting to network: mainnet
INFO [05-20|23:52:48] Latest local block: number=0 td=17179869184 hash=d4e56740...
INFO [05-20|23:52:48] Synchronizing blockchain...
INFO [05-20|23:52:48] Started rlpx server.
INFO [05-20|23:52:48] Started libp2p server.
INFO [05-20|23:52:53] Listener up transport=rlpx url=enode://13fc4c166a7265c38a8d71df20d1b85b7cefeb678f870b065c1796fff3e8213e7d7fe28937dc21469e547493afca96dba9697604e5f85a1f56173d1d6bb76394@[::]:30303
INFO [05-20|23:52:53] Listener up transport=libp2p url=/p2p-circuit/ipfs/QmaobEUntyrxsi5EYYnvUcTS1DLP6rpDBiVCifW59nB46G
INFO [05-20|23:52:53] Listener up transport=libp2p url=/p2p-circuit/ip4/127.0.0.1/tcp/50580/ws/ipfs/QmaobEUntyrxsi5EYYnvUcTS1DLP6rpDBiVCifW59nB46G
INFO [05-20|23:52:53] Listener up transport=libp2p url=/ip4/127.0.0.1/tcp/50580/ws/ipfs/QmaobEUntyrxsi5EYYnvUcTS1DLP6rpDBiVCifW59nB46G
INFO [05-20|23:52:53] Started eth service.
ERROR [05-20|23:53:28] Error: Request timed out after 5000ms
    at Timeout._onTimeout (ethereumjs-client/lib/net/protocol/boundprotocol.js:129:16)
    at listOnTimeout (internal/timers.js:531:17)
    at processTimers (internal/timers.js:475:7)
ERROR [05-20|23:53:34] Error: Request timed out after 5000ms
    at Timeout._onTimeout (ethereumjs-client/lib/net/protocol/boundprotocol.js:129:16)
    at listOnTimeout (internal/timers.js:531:17)
    at processTimers (internal/timers.js:475:7)
ERROR [05-20|23:53:40] Error: Request timed out after 5000ms
    at Timeout._onTimeout (ethereumjs-client/lib/net/protocol/boundprotocol.js:129:16)
    at listOnTimeout (internal/timers.js:531:17)
    at processTimers (internal/timers.js:475:7)
ERROR [05-20|23:53:46] Error: Request timed out after 5000ms

[coveralls]

Coverage increased (+0.1%) to 92.672% when pulling 7346d03 on basic-library-fixes into ddef972 on master.

[PhilippLgh]

Logs say transport=libp2p or this unrelated?

[holgerd77]

First entry on this is transport=rlpx, I think both transports are opened at the same time, so this is likely unrelated.

[holgerd77]

Just gave this a bit more time, works! 😀 🎉

(several other things to fix here though)

But then I would say we can release on the devp2p side! 😄

As some note: transport debugging for the client can be done with

DEBUG=devp2p:rlpx,devp2p:eth,-babel ethereumjs

(also noted in the README). Filter values for the logger can also be replaced with something else, this -babel is to cut out noise.