restructure imageproxy package

- move binary from imageproxy.go to cmd/imageproxy/main.go
- move proxy package up to top level

cmd/imageproxy/main.go

@@ -0,0 +1,76 @@
+// Copyright 2013 Google Inc. All rights reserved.
+//
+// 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.
+
+// imageproxy starts an HTTP server that proxies requests for remote images.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"strings"
+
+	"github.com/gregjones/httpcache"
+	"github.com/gregjones/httpcache/diskcache"
+	"willnorris.com/go/imageproxy"
+)
+
+// goxc values
+var (
+	// VERSION is the version string for imageproxy.
+	VERSION = "HEAD"
+
+	// BUILD_DATE is the timestamp of when imageproxy was built.
+	BUILD_DATE string
+)
+
+var addr = flag.String("addr", "localhost:8080", "TCP address to listen on")
+var whitelist = flag.String("whitelist", "", "comma separated list of allowed remote hosts")
+var cacheDir = flag.String("cacheDir", "", "directory to use for file cache")
+var version = flag.Bool("version", false, "print version information")
+
+func main() {
+	flag.Parse()
+
+	if *version {
+		fmt.Printf("%v\nBuild: %v\n", VERSION, BUILD_DATE)
+		return
+	}
+
+	var c httpcache.Cache
+	if *cacheDir != "" {
+		c = diskcache.New(*cacheDir)
+	} else {
+		c = httpcache.NewMemoryCache()
+	}
+
+	p := imageproxy.NewProxy(nil, c)
+	p.MaxWidth = 2000
+	p.MaxHeight = 2000
+	if *whitelist != "" {
+		p.Whitelist = strings.Split(*whitelist, ",")
+	}
+
+	server := &http.Server{
+		Addr:    *addr,
+		Handler: p,
+	}
+
+	fmt.Printf("imageproxy (version %v) listening on %s\n", VERSION, server.Addr)
+	err := server.ListenAndServe()
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}