Extract portforward to separate package (#728)

* Extract port-forward from CLI to own package (for reuseability)
* Extract CLI logging to subpackage

fission/log/log.go

@@ -0,0 +1,42 @@
+/*
+Copyright 2016 The Fission Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package log
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	// global Verbosity of our CLI
+	Verbosity int
+)
+
+func Fatal(msg interface{}) {
+	os.Stderr.WriteString(fmt.Sprintf("%v\n", msg))
+	os.Exit(1)
+}
+
+func Warn(msg interface{}) {
+	os.Stderr.WriteString(fmt.Sprintf("%v\n", msg))
+}
+
+func Verbose(verbosityLevel int, format string, args ...interface{}) {
+	if Verbosity >= verbosityLevel {
+		fmt.Printf(format+"\n", args...)
+	}
+}