API Coordinator Refactor

Test L2Txs, ExitTree in synchronizer

StateDB store Idxs with TokenID at the db-key & TxSelector include L1CoordinatorTxs in selections

ProcessTxs return an array of created accounts

API Update tokens endpoint

Add struct get state endpoint

Add ProcessTxs send fees to Coordinator accounts

Update Synchroinzer and tests

- Test L1UserTxs in Synchronizer
- Test Batches in Synchronizer
- Add last_idx in `TABLE batch` in HistoryDB
- Minor updates in til to satisfy blockchain constraints

Feature/eth remove erc777

Feature/api batches

Impl account creation auth endpoints

Feature/fees update

Add the ability to run the API forever when testing

Add TxTypeTransferToEthAddr&ToBJJ to StateDB & Til

Add TxTypeTransferToEthAddr&ToBJJ to StateDB & Til
resolves #203, resolves #209

In til, process L1UserTxs when defined, not in batch

Update missing parts, improve til, and more

- Node
	- Updated configuration to initialize the interface to all the smart
	  contracts
- Common
	- Moved BlockData and BatchData types to common so that they can be
	  shared among: historydb, til and synchronizer
	- Remove hash.go (it was never used)
	- Remove slot.go (it was never used)
	- Remove smartcontractparams.go (it was never used, and appropriate
	  structs are defined in `eth/`)
	- Comment state / status method until requirements of this method are
	  properly defined, and move it to Synchronizer
- Synchronizer
	- Simplify `Sync` routine to only sync one block per call, and return
	  useful information.
	- Use BlockData and BatchData from common
	- Check that events belong to the expected block hash
	- In L1Batch, query L1UserTxs from HistoryDB
	- Fill ERC20 token information
	- Test AddTokens with test.Client
- HistryDB
	- Use BlockData and BatchData from common
	- Add `GetAllTokens` method
	- Uncomment and update GetL1UserTxs (with corresponding tests)
- Til
	- Rename all instances of RegisterToken to AddToken (to follow the smart
	  contract implementation naming)
	- Use BlockData and BatchData from common
		- Move testL1CoordinatorTxs and testL2Txs to a separate struct
		  from BatchData in Context
	- Start Context with BatchNum = 1 (which the protocol defines to be the
	  first batchNum)
	- In every Batch, set StateRoot and ExitRoot to a non-nil big.Int
	  (zero).
	- In all L1Txs, if LoadAmount is not used, set it to 0; if Amount is not
	  used, set it to 0; so that no *big.Int is nil.
	- In L1UserTx, don't set BatchNum, because when L1UserTxs are created
	  and obtained by the synchronizer, the BatchNum is not known yet (it's
	  a synchronizer job to set it)
	- In L1UserTxs, set `UserOrigin` and set `ToForgeL1TxsNum`.

Calulate total collected batch fee and fix merkleproof api format

Coordinators methods for API

Implement tx pool endpoints

Update Til with small fixes:
- L2Tx TxID & Type correctness done after Idxs setted
- Added PoolL2Tx signature for Exit type

Common:
- Add common.TxID Marshalers test

Feature/til update

Rename Transakcio to Til for a easier usage, also change til.TestContext
to til.Context, and til.NewTestContext to til.NewContext.

Add config endpoint

Feature/update general