EVM Transaction handler and contract creation (#96)

* WIP implementing state transition function

* Error handling and application setup fix

* Fixed error comment

* Allow creation of state objects with a BaseAccount

* Fixed parameters and finalise state after transaction

* updated transaction signing and cli signature

* Set up consistent account encoding and decoding

* Update txbuilder to get sequence before generating eth tx

* Added create functionality to the CLI command

* Remove need to copy over context for statedb interactions

* Updated account retriever

* Cleaned up handler code and updated TODO

* Make recoverEthSig private again

* Add error check for committing to kv store

* Remove commented out code

* Update evm chain config for state transition

* Add time in context for dapps

x/evm/types/chain_config.go

@@ -0,0 +1,26 @@
+package types
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// GenerateChainConfig returns an Ethereum chainconfig for EVM state transitions
+func GenerateChainConfig(chainID *big.Int) *params.ChainConfig {
+	// TODO: Update chainconfig to take in parameters for fork blocks
+	return &params.ChainConfig{
+		ChainID:             chainID,
+		HomesteadBlock:      big.NewInt(0),
+		DAOForkBlock:        big.NewInt(0),
+		DAOForkSupport:      true,
+		EIP150Block:         big.NewInt(0),
+		EIP150Hash:          common.HexToHash("0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0"),
+		EIP155Block:         big.NewInt(0),
+		EIP158Block:         big.NewInt(0),
+		ByzantiumBlock:      big.NewInt(0),
+		ConstantinopleBlock: big.NewInt(0),
+		PetersburgBlock:     big.NewInt(0),
+	}
+}

x/evm/types/state_object.go

@@ -80,7 +80,12 @@ type (
 func newObject(db *CommitStateDB, accProto auth.Account) *stateObject {
 	acc, ok := accProto.(*types.Account)
 	if !ok {
-		panic(fmt.Sprintf("invalid account type for state object: %T", acc))
+		// State object can be created from a baseAccount
+		baseAccount, ok := accProto.(*auth.BaseAccount)
+		if !ok {
+			panic(fmt.Sprintf("invalid account type for state object: %T", accProto))
+		}
+		acc = &types.Account{BaseAccount: baseAccount}
 	}
 
 	if acc.CodeHash == nil {