p2p/protocols, p2p/testing: protocol abstraction and testing

cmd/faucet: resolve twitter user from final redirect

cmd/puppeth: Don't allow hyphen in network name. Fixes #16155

accounts/abi: Fix the bug of mobile framework crashing

accounts/abi: add another unpack interface

* ethapi: prevent creating contract if no data is provided

* internal/ethapi: downcase error for no data on contract creation

This change removes a peer information from dialing history
when peer is removed from static list. It allows to force a
server to re-dial concrete peer if it is needed.

In our case we are running geth node on mobile devices, and
it is common for a network connection to flap on mobile.
Almost every time it flaps or network connection is changed
from cellular to wifi peers are disconnected with read
timeout. And usually it takes 30 seconds (default expiration
timeout) to recover connection with static peers after
connectivity is restored.

This change allows us to reconnect with peers almost
immediately and it seems harmless enough.

cmd, console: support all termination signals

* README: add goreportcard.com badge to Readme

* README: fix double github.com

* les: fix light fetcher database race

* les: lightFetcher comments

vendor: update rjeczalik/notify so that it compiles on go1.10

Handle all expectations in ProtocolSession.TestExchanges in any
order that are received.

p2p/discover: validate bond against lastpong, not db presence

I forgot to change the check in udp.go when I changed Table.bond to be
based on lastPong instead of node presence in db. Rename lastPong to
bondTime and add hasBond so it's clearer what this DB key is used for
now.

* swarm: added script to HTML header to create favicon addresses #153

* swarm: moved data blob direclty into link tag, removed script

* swarm: added favicon info to other html templates

* swarm: fixing test errors

* swarm: fixing favicon test

* swarm: fixing travis tests

* swarm: added script to HTML header to create favicon addresses #153

* swarm: moved data blob direclty into link tag, removed script

* swarm: added favicon info to other html templates

* swarm: fixing test errors

* swarm: fixing favicon test

* swarm: fixing travis tests

This is in preparation for the switch to libp2p: the ID generated
will be from a private key created with the help of libp2p's crypto
library, while Whisper will still use Go's default crypto libraries
for encrypting its messages. This change removes a conflict.

It shouldn't have any impact as the person receiving emails is
the user, not the node.

* whisper: timeout extended

* whisper: test updated

* whisper: test updated

les: add missing lock around peer access

main: add gc flags to import-command

- according to implementation of `IntrinsicGas`
we can continue execution since problem will be detected
later. However, early return is future-proof for changes.