Merge proxy and router/weaver processes.

Note: we no longer need to detect awsvpc when launching.
The "AWS VPC" mode is now set via the `--awsvpc` flag.
Before we had to "detect" it when the proxy was potentially started
later, after the router had started.

We drop WEAVEPROXY_DOCKER_ARGS as obsolete.

proxy/proxy.go

@@ -204,7 +204,7 @@ func (proxy *Proxy) findWeaveWaitVolumes() error {
 }
 
 func (proxy *Proxy) findVolume(v string) (string, error) {
-	container, err := proxy.client.InspectContainer("weaveproxy")
+	container, err := proxy.client.InspectContainer("weave")
 	if err != nil {
 		return "", fmt.Errorf("Could not find the weavewait volume: %s", err)
 	}