[streaming] DataStream print functionality update

PrintSinkFunction now explicitly states threads in output
Added printToErr functionality
[streaming] [examples] Refactor and packaging for windowing examples

The current examples show-case the API, more meaningful examples are coming for the 0.9 release.
[streaming] Updated deprecated iterative functionality and docs
[FLINK-1325] [streaming] Added clousure cleaning to streaming

This closes #273
Fix invalid type hierarchy creation by Pojo logic
[FLINK-610] Replace Avro by Kryo as the GenericType serializer

The performance of data-intensive jobs using Kryo is probably going to be slow.

Set correct classloader

try to use Kryo.copy() with fallback to serialization copy
[FLINK-1333] Fixed getter/setter recognition for POJOs

This closes #271
Fixes race condition in ExecutionGraph which allowed a job to go into the finished state without all job vertices having properly processed the finalizeOnMaster method.
[FLINK-1336] [core] Fix bug in StringValue binary copy method
[streaming] StreamInvokable rework for simpler logic and easier use
[dist] Updated the assembly of the examples subdirectory

Excluded the scala example jars
Excluded the example source code subdirectories

This closes #274
[streaming] Added immutability for window and filter operators
[streaming] Make windowed data stream aware of time based trigger/eviction in tumbling window situations.

[streaming] Changed TimeEvictionPolicy to keep timestamps in the buffer instead of data-items