Added Zihong Cao to CONTRIBUTORS list

[ci skip]
This closes #21
Added configuration subsection in webinterface

Closes #16 (GitHub pull request)
Also closes FLINK-919
New Webclient

This closes #15
and FLINK-711
Fixed error messages in web client
extended plan-dump test for KMeans
Fixed JSON Bug for some plans.

Signed-off-by: Robert Metzger <metzgerr@web.de>

This closes #23.
Add log info message with memory usage after TaskManager startup finished.

This commit also introduces a logging thread, which repeatedly logs the
memory usage. It can be configured via:
    - 'taskmanager.debug.memory.startLogThread' (default: false)
    - 'taskmanager.debug.memory.logIntervalMs' (default: 5000)
Remove Parameterized test runner annotation from NettyConnectionManagerTest
[FLINK-940] Added additional test for cogroup with delta iteration solution set on second input.
[FLINk-941] Place pipeline breakers for SingleInput nodes with broadcast variables, if needed.
[FLINK-950] Fix spurious file deletion failures.
Projection constructor adjusts to max tuple size

This closes #27
[FLINK-943] Remove leading and ending double quotes from 'env.java.opts' config value in startup scripts

This closes #26
Transitive closure example in Java API

This closes #24
[FLINK-944] CollectionInputFormat now uses the TypeSerializer to serialize the collection entries. This allows to use objects not implementing the Serializable interface as collection elements.

This closes #25
[FLINK-944] Consolidated serialization logic between different classes. Fixes for warnings.
Re-encrypt the credentials for various services with the new apache/incubator-flink travis keys
Syntactic sugar for sum, min, and max aggregations

This closes #7
[FLINK-957] Throw meaningful warnings and exceptions upon incorrect use of delta iterations.
Added Version and Revision of Stratosphere in Webinterface

https://issues.apache.org/jira/browse/FLINK-946

![bildschirmfoto 2014-06-20 um 14 43 26](https://cloud.githubusercontent.com/assets/5738978/3340103/82d0485e-f878-11e3-9d15-617102ea40a3.png)

Author: Jonathan <Jonathan@Hasenburg.de>

Closes #30 from JonathanH5/wi_version and squashes the following commits:

f29180a [Jonathan] Added Version and Revision of Stratosphere in Webinterface