all: clean up and proerly abstract database access

les/backend.go

@@ -79,7 +79,7 @@ type LightEthereum struct {
 }
 
 func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
-	chainDb, err := eth.CreateDB(ctx, config, "lightchaindata")
+	chainDb, err := ctx.OpenDatabase("lightchaindata", config.DatabaseCache, config.DatabaseHandles, "eth/db/chaindata/")
 	if err != nil {
 		return nil, err
 	}