When querying the init event for each smart contract, bound the search from
block genesis-24h to block genesis.  Otherwise, this query in geth synced to
mainnet takes too long.

Updated:
	batchbuilder
	common
	coordinator
	db/statedb
	eth
	log
	node
	priceupdater
	prover
	synchronizer
	test/*
	txprocessor
	txselector

Pending (once
https://github.com/hermeznetwork/hermez-node/tree/feature/serveapicli is
merged to master):
	Update golangci-lint version to v1.37.1
	api
	apitypes
	cli
	config
	db/historydb
	db/l2db

- kvdb
	- Fix path in Last when doing `setNew`
	- Only close if db != nil, and after closing, always set db to nil
		- This will avoid a panic in the case where the db is closed but
		  there's an error soon after, and a future call tries to close
		  again.  This is because pebble.Close() will panic if the db is
		  already closed.
	- Avoid calling pebble methods when a the Storage interface already
	  implements that method (like Close).
- statedb
	- In test, avoid calling KVDB method if the same method is available for
	  the StateDB (like MakeCheckpoint, CurrentBatch).
- eth
	- In *EventByBlock methods, take blockHash as input argument and use it
	  when querying the event logs.  Previously the blockHash was only taken
	  from the logs results *only if* there was any log.  This caused the
	  following issue: if there was no logs, it was not possible to know if
	  the result was from the expected block or an uncle block!  By querying
	  logs by blockHash we make sure that even if there are no logs, they
	  are from the right block.
	  	- Note that now the function can either be called with a
		  blockNum or blockHash, but not both at the same time.
- sync
	- If there's an error during call to Sync call resetState, which
	  internally resets the stateDB to avoid stale checkpoints (and a
	  corresponding invalid increase in the StateDB batchNum).
	- During a Sync, after very batch processed, make sure that the StateDB
	  currentBatch corresponds to the batchNum in the smart contract
	  log/event.

- API:
	- Modify the constructor so that hardcoded rollup constants don't need
	  to be passed (introduce a `Config` and use `configAPI` internally)
- Common:
	- Update rollup constants with proper *big.Int when required
	- Add BidCoordinator and Slot structs used by the HistoryDB and
	  Synchronizer.
	- Add helper methods to AuctionConstants
	- AuctionVariables: Add column `DefaultSlotSetBidSlotNum` (in the SQL
	  table: `default_slot_set_bid_slot_num`), which indicates at which
	  slotNum does the `DefaultSlotSetBid` specified starts applying.
- Config:
	- Move coordinator exclusive configuration from the node config to the
	  coordinator config
- Coordinator:
	- Reorganize the code towards having the goroutines started and stopped
	  from the coordinator itself instead of the node.
	- Remove all stop and stopped channels, and use context.Context and
	  sync.WaitGroup instead.
	- Remove BatchInfo setters and assing variables directly
	- In ServerProof and ServerProofPool use context instead stop channel.
	- Use message passing to notify the coordinator about sync updates and
	  reorgs
	- Introduce the Pipeline, which can be started and stopped by the
	  Coordinator
	- Introduce the TxManager, which manages ethereum transactions (the
	  TxManager is also in charge of making the forge call to the rollup
	  smart contract).  The TxManager keeps ethereum transactions and:
	  	1. Waits for the transaction to be accepted
		2. Waits for the transaction to be confirmed for N blocks
	- In forge logic, first prepare a batch and then wait for an available
	  server proof to have all work ready once the proof server is ready.
	- Remove the `isForgeSequence` method which was querying the smart
	  contract, and instead use notifications sent by the Synchronizer to
	  figure out if it's forging time.
	- Update test (which is a minimal test to manually see if the
	  coordinator starts)
- HistoryDB:
	- Add method to get the number of batches in a slot (used to detect when
	  a slot has passed the bid winner forging deadline)
	- Add method to get the best bid and associated coordinator of a slot
	  (used to detect the forgerAddress that can forge the slot)
- General:
	- Rename some instances of `currentBlock` to `lastBlock` to be more
	  clear.
- Node:
	- Connect the API to the node and call the methods to update cached
	  state when the sync advances blocks.
	- Call methods to update Coordinator state when the sync advances blocks
	  and finds reorgs.
- Synchronizer:
	- Add Auction field in the Stats, which contain the current slot with
	  info about highest bidder and other related info required to know who
	  can forge in the current block.
	- Better organization of cached state:
		- On Sync, update the internal cached state
		- On Init or Reorg, load the state from HistoryDB into the
		  internal cached state.

- Move smart contract constants and structs for variables to
  common/{ethrollup.go, ethauction.go, ethwdelayer.go}:
    - This removes repeated code of the structs for variables
    - Allows reusing the constants and variables from all modules without
      import cycles
- Remove unused common/scvars.go
- In common.BlockData, split data from each smart contract into a sepparate
  field (Rollup, Auction, WDelayer).  This affects the structures that til uses
  as output, and HistoryDB in the AddBlockSCData.
- In Synchronizer:
    - Pass starting block of each smart contract as config, instead of
      incorrectly using the genesis block found in the acution constant (which
      has a very different meaning)
    - Use variable structs from common instead of an internal copy
    - Synchronize more stuff (resolve some TODOs)
    - Fix some issues found after initial testing with ganache
- In eth:
    - In auction.go: Add method to get constants
    - Update README to use ganache instead of buidlerevm as local blockchain
      for testing
    - Update env variables and test vectors to pass the tests with the
      deployment in the ganache testnet.
    - Use ethereum keys derived from paths (hdwallet) in testing to avoid
      hardcoding private keys and generate the same keys from a mnemonic used
      in the ganache tesnet.