Previously the Synchronizer required the initial variables of the smart
contracts to be passed as a configuration parameter (that the node took from
the configuration file).  The same applied to the blockNumber.

The last update of the smart contracts introduced events for each smart
contract constructor (initializer), which allows querying the initial variables
as well as the initial block number for each smart contract.

Now the synchronizer uses this information, and thus the initial variables and
the starting block numbers have been removed from the configuration.

- API:
	- Replace `emergencyModeStaringTime` by `emercengyModeStartingBlock`
- Synchronizer:
	- Track emergency mode starting block
- cli/node
	- Add working coordinator config
- coordinator:
	- Retry handler for synchronizer stats in case of error (instead of
	  waiting for the next block to try again)
	- On init, trigger an initial call to the handler for synced block
	  before waiting for the synchronizer, to force the coordinator to start
	  its logic even if there's no new block right after the node has been
	  started (very useful for running in testnet where the frequency of
	  blocks is variable)
	- Merge Msg for synced block and updated vars into one: `MsgSyncBlock`.

- Common
	- Move ErrTODO and ErrDone to common for usage where needed.
- Coordinator
	- Move prover types to prover package
	- Handle reorgs, stopping the pipeline when necessary
	- Handle ethereum transaction errors by stopping the pipeline
	- In case of ethereum transaction revert, check for known revert causes
	  (more revert causes can be added to handle more cases)
	- Fix skipped transactions in TxManager confirmation logic
	- Cancel and wait for provers to be ready
	- Connect L2DB to:
		- purge l2txs due to timeout
		- mark l2txs at the different states
	- Connect HistoryDB to query L1UserTxs to forge in an L1Batch
- L2DB
	- Skip update functions when the input slices have no values (to avoid a
	  query with no values that results in an SQL error)
- StateDB
	- In LocalStateDB, fix Reset when mt == nil
- Prover (new package)
	- Rename the interface to Prover
	- Rename the mock struct to Mock
	- Extend Prover interface methods to provide everything required by the
	  coordinator
	- Begin implementing required http client code to interact with server
	  proof (not tested)
- Synchronizer:
	- Add LastForgeL1TxsNum to Stats
- Test/Client
	- Update Auction logic to track slots in which there's no forge during
	  the time before the deadline (following the solidity implementation)

- 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.