Implemented new miner w/ ui interface for merged mining. Closes #177

* Miner has been rewritten
* Added new miner pane
* Added option for local txs
* Added option to read from MergeMining contract and list them for
  merged mining

chain/dagger.go

@@ -47,6 +47,7 @@ func (pow *EasyPow) Search(block *Block, stop <-chan struct{}) []byte {
 		select {
 		case <-stop:
 			powlogger.Infoln("Breaking from mining")
+			pow.HashRate = 0
 			return nil
 		default:
 			i++
@@ -55,7 +56,7 @@ func (pow *EasyPow) Search(block *Block, stop <-chan struct{}) []byte {
 				elapsed := time.Now().UnixNano() - start
 				hashes := ((float64(1e9) / float64(elapsed)) * float64(i)) / 1000
 				pow.HashRate = int64(hashes)
-				powlogger.Infoln("Hashing @", int64(pow.HashRate), "khash")
+				powlogger.Infoln("Hashing @", pow.HashRate, "khash")
 
 				t = time.Now()
 			}