Use a vendor directory for repeatable builds - fixes #816

This is using godep to manage the vendor directory.

vendor/google.golang.org/appengine/timeout.go

@@ -0,0 +1,49 @@
+// Copyright 2013 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package appengine
+
+import (
+	"time"
+
+	"github.com/golang/protobuf/proto"
+
+	"google.golang.org/appengine/internal"
+)
+
+// IsTimeoutError reports whether err is a timeout error.
+func IsTimeoutError(err error) bool {
+	if t, ok := err.(interface {
+		IsTimeout() bool
+	}); ok {
+		return t.IsTimeout()
+	}
+	return false
+}
+
+// Timeout returns a replacement context that uses d as the default API RPC timeout.
+func Timeout(c Context, d time.Duration) Context {
+	return &timeoutContext{
+		Context: c,
+		d:       d,
+	}
+}
+
+type timeoutContext struct {
+	Context
+	d time.Duration
+}
+
+func (t *timeoutContext) Call(service, method string, in, out proto.Message, opts *internal.CallOptions) error {
+	// Only affect calls that don't have a timeout.
+	if opts == nil || opts.Timeout == 0 {
+		newOpts := new(internal.CallOptions)
+		if opts != nil {
+			*newOpts = *opts
+		}
+		newOpts.Timeout = t.d
+		opts = newOpts
+	}
+	return t.Context.Call(service, method, in, out, opts)
+}