Convert request factory components into a module

Move all of the code to create the request factories into
RequestFactoryModule.  Also add the --force_http_connection flag to allow us
to force the use of HTTP connections instead of HTTPOverRPC for our internal
connections.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=146116640

java/google/registry/tools/RegistryToolComponent.java

@@ -38,10 +38,12 @@ import javax.inject.Singleton;
 @Singleton
 @Component(
   modules = {
-    AppEngineConnectionFlagsModule.class,
+    AppEngineConnectionFlags.FlagsModule.class,
     ConfigModule.class,
     DatastoreServiceModule.class,
     CloudDnsWriterModule.class,
+    DefaultRequestFactoryModule.class,
+    DefaultRequestFactoryModule.RequestFactoryModule.class,
     DnsUpdateWriterModule.class,
     DummyKeyringModule.class,
     Jackson2Module.class,
@@ -52,9 +54,6 @@ import javax.inject.Singleton;
     URLFetchServiceModule.class,
     VoidDnsWriterModule.class,
     WhoisModule.class,
-  },
-  dependencies = {
-    HttpRequestFactoryComponent.class,
   }
 )
 interface RegistryToolComponent {