[release/1.4.8] test, cmd/evm, core, core/vm: illegal code hash implementation

This implements a generic approach to enabling soft forks by allowing
anyone to put in hashes of contracts that should not be interacted from.
This will help "The DAO" in their endevour to stop any whithdrawals from
any DAO contract by convincing the mining community to accept their code
hash.

(cherry picked from commit 7a5b571c67)

core/vm/runtime/runtime.go

@@ -35,17 +35,18 @@ func (ruleSet) IsHomestead(*big.Int) bool { return true }
 // Config is a basic type specifying certain configuration flags for running
 // the EVM.
 type Config struct {
-	RuleSet     vm.RuleSet
-	Difficulty  *big.Int
-	Origin      common.Address
-	Coinbase    common.Address
-	BlockNumber *big.Int
-	Time        *big.Int
-	GasLimit    *big.Int
-	GasPrice    *big.Int
-	Value       *big.Int
-	DisableJit  bool // "disable" so it's enabled by default
-	Debug       bool
+	RuleSet       vm.RuleSet
+	Difficulty    *big.Int
+	Origin        common.Address
+	Coinbase      common.Address
+	BlockNumber   *big.Int
+	Time          *big.Int
+	GasLimit      *big.Int
+	GasPrice      *big.Int
+	Value         *big.Int
+	DisableJit    bool // "disable" so it's enabled by default
+	Debug         bool
+	illegalHashes []common.Hash
 
 	State     *state.StateDB
 	GetHashFn func(n uint64) common.Hash