cmd, core, params: add --rinkeby flag for fast connectivity

* core: Fix for consensus test gasLimit > 2^63-1 https://github.com/ethereum/tests/blob/develop/BlockchainTests/bcInvalidHeaderTest.json#L238

* core: fix testcase for uncle gasUsage > gasLimit : https://github.com/ethereum/tests/blob/develop/BlockchainTests/EIP150/bcUncleHeaderValiditiy.json#L986

* math/big: rename TTM63m1 -> MaxBig63, + go fmt

* core: documentation

Migrate remaining flags/command to new style

cmd/faucet, cmd/puppeth: support multi-tiered faucet

build: wnode added to the build configuration

cmd/geth, cmd/utils: init/removedb on light/full dbs simultaneously

consensus/clique: fix overflow on recent signer check around genesis

rpc: support subscriptions under custom namespaces

README: add config to genesis.json

consensus/ethash: fix a timestamp update race

eth/downloader: fix a potential issue against future refactors

console: avoid float64 when remarshaling parameters

rpc: disable CORS if user has not specified a custom config

With Go 1.7, encoding/json marshals float64 using scientific
notation ("10e+6"), but Go's int and *big.Int decoders don't accept such
numbers. This change disables use of float64 to avoid the problem.

cmd/geth: reorganise account/wallet command/flags

* whisper: salt removed from AES encryption
* whisper: padding format updated
* whisper: padding test added
* whisper: padding refactored, tests fixed
* whisper: padding test updated
* whisper: wnode bugfix
* whisper: send/receive protocol updated
* whisper: minor update
* whisper: bugfix in test
* whisper: updated parameter names and comments
* whisper: functions renamed
* whisper: minor refactoring

node: fixes deadlock on Wait()

cmd, eth, les, mobile: make networkid uint64 everywhere