cmd, eth: added light client and light server modes

ethdb/database.go

@@ -40,13 +40,15 @@ var OpenFileLimit = 64
 // cacheRatio specifies how the total allotted cache is distributed between the
 // various system databases.
 var cacheRatio = map[string]float64{
-	"chaindata": 1.0,
+	"chaindata":      1.0,
+	"lightchaindata": 1.0,
 }
 
 // handleRatio specifies how the total allotted file descriptors is distributed
 // between the various system databases.
 var handleRatio = map[string]float64{
-	"chaindata": 1.0,
+	"chaindata":      1.0,
+	"lightchaindata": 1.0,
 }
 
 type LDBDatabase struct {