[FLINK-1346] [docs] Add stubs for Akka documentation

docs/config.md

@@ -226,6 +226,23 @@ heartbeats to the JobManager.
 - `jobmanager.max-heartbeat-delay-before-failure.msecs`: The maximum time that a
 TaskManager hearbeat may be missing before the TaskManager is considered failed.
 
+### Distributed Coordination (via Akka)
+
+- `akka.startup-timeout`: 
+- `akka.transport.heartbeat.interval`: 
+- `akka.transport.heartbeat.pause`: 
+- `akka.transport.threshold`: 
+- `akka.watch.heartbeat.interval`: 
+- `akka.watch.heartbeat.pause`: 
+- `akka.watch.threshold`: 
+- `akka.tcp.timeout`: 
+- `akka.framesize`: 
+- `akka.throughput`: 
+- `akka.log.lifecycle.events`: 
+- `akka.loglevel`: 
+- `akka.ask.timeout`: 
+
+
 ### JobManager Web Frontend
 
 - `jobmanager.web.port`: Port of the JobManager's web interface that displays

docs/internal_distributed_akka.md

+---
+title:  "Distributed Communication and Coordination via Akka"
+---
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you 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.
+-->
+
+This page discusses the implementation of Flink's distributed communication
+via Akka (http://akka.io)
+
+
+## Actor Systems
+
+### JobManager
+
+### TaskManager
+
+### JobClient
+
+
+## Actors and Messages
+
+
+## Failure Detection
+
+

docs/internal_overview.md

@@ -35,7 +35,11 @@ or pull request that updates these documents as well.*
 
 <!--
 - [Life Cycle of a Program](program_life_cycle.html)
+-->
+
+- [Distributed Communication via Akka](internal_distributed_akka.html)
 
+<!--
 - [Jobs and Scheduling](job_scheduling.html)
 
 - [Distributed Runtime](distributed_runtime.html)
@@ -51,8 +55,4 @@ or pull request that updates these documents as well.*
 - [Java API, Types, and Type Extraction](types.html)
 -->
 
-<!--
-- [RPC and JobManager Communication](rpc_transfer.html)
--->
-
-- [How-to: Using logging in Flink](internal_logging.html)
\ No newline at end of file
+- [How-to: Using logging in Flink](internal_logging.html)