vendor: add github.com/diegomarangoni/gcscache

also include all transitive dependencies of gcscache, which seems to
bring in the entire world of Google Cloud Platform.

vendor/google.golang.org/api/gensupport/params.go

@@ -0,0 +1,50 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gensupport
+
+import (
+	"net/url"
+
+	"google.golang.org/api/googleapi"
+)
+
+// URLParams is a simplified replacement for url.Values
+// that safely builds up URL parameters for encoding.
+type URLParams map[string][]string
+
+// Get returns the first value for the given key, or "".
+func (u URLParams) Get(key string) string {
+	vs := u[key]
+	if len(vs) == 0 {
+		return ""
+	}
+	return vs[0]
+}
+
+// Set sets the key to value.
+// It replaces any existing values.
+func (u URLParams) Set(key, value string) {
+	u[key] = []string{value}
+}
+
+// SetMulti sets the key to an array of values.
+// It replaces any existing values.
+// Note that values must not be modified after calling SetMulti
+// so the caller is responsible for making a copy if necessary.
+func (u URLParams) SetMulti(key string, values []string) {
+	u[key] = values
+}
+
+// Encode encodes the values into ``URL encoded'' form
+// ("bar=baz&foo=quux") sorted by key.
+func (u URLParams) Encode() string {
+	return url.Values(u).Encode()
+}
+
+func SetOptions(u URLParams, opts ...googleapi.CallOption) {
+	for _, o := range opts {
+		u.Set(o.Get())
+	}
+}