[release/1.3.4] parmas, crypto, core, core/vm: homestead consensus protocol changes

* change gas cost for contract creating txs
* invalidate signature with s value greater than secp256k1 N / 2
* OOG contract creation if not enough gas to store code
* new difficulty adjustment algorithm
* new DELEGATECALL op code

Conflicts:
	core/vm/environment.go
	crypto/crypto.go
	crypto/secp256k1/secp256.go
	eth/api.go

core/vm/contract.go

@@ -26,11 +26,13 @@ import (
 type ContractRef interface {
 	ReturnGas(*big.Int, *big.Int)
 	Address() common.Address
+	SetAddress(common.Address)
+	Value() *big.Int
 	SetCode([]byte)
 }
 
 // Contract represents an ethereum contract in the state database. It contains
-// the the contract code, calling arguments. Contract implements ContractReg
+// the the contract code, calling arguments. Contract implements ContractRef
 type Contract struct {
 	caller ContractRef
 	self   ContractRef
@@ -44,6 +46,8 @@ type Contract struct {
 	value, Gas, UsedGas, Price *big.Int
 
 	Args []byte
+
+	DelegateCall bool
 }
 
 // Create a new context for the given data items.
@@ -113,6 +117,16 @@ func (c *Contract) Address() common.Address {
 	return c.self.Address()
 }
 
+// SetAddress sets the contracts address
+func (c *Contract) SetAddress(addr common.Address) {
+	c.self.SetAddress(addr)
+}
+
+// Value returns the contracts value (sent to it from it's caller)
+func (c *Contract) Value() *big.Int {
+	return c.value
+}
+
 // SetCode sets the code to the contract
 func (self *Contract) SetCode(code []byte) {
 	self.Code = code