This closes #1009

PlanBinder methods were restructured to make the class more readable.

Keys are now stored as strings to simplify string-key-expression support.
Parameter retrieval was moved from PB to OI constructor, similiar to PythonOperationInfo.
This change reduces the clutter in Planbinder and allows code reusage for operations with similar parameters.

This closes #961

 - extended TupleType helper classes to handle Tuple0
 - extended TupleSerializer to handle Tuple0
 - included Tuple0 into JUnit tests
 - simplified Receiver.createTuple(int)

This closes #983

This closes #1013

Correcting commit, because the wrong commit was pushed earlier.

1. Allow access to Runtime Context from I/O formats.
2. Make all existing I/O formats context aware.

This closes #966.

[CLEANUP] Add space between quotes and plus sign in String concat for readability in flink-yarn module

While working on Flink on YARN, do some simple nit cleanups to add space between quote and plus sign for readability in yarn module for readability.

Use StringBuilder instad of StringBuffer in FlinkYarnClient since the String materializes immediately, so no need synchronize protection.

Author: hsaputra <hsaputra@apache.org>

Closes #1010 from hsaputra/cleanup_yarn_branch and squashes the following commits:

a6fc9e1 [hsaputra] Add space between quote and plus sign for readability in flink-yarn module.

regression of c6358024

Also changed some prints which printed the word "class" twice,
because class.toString also prepends it to the class name.

This closes #960.

Closes #1007

[FLINK-2509] [runtime] Add class loader info into the exception message when user code classes are not found.

This closes #1008

Closes #980

This closes #1005

This closes #1001

 - added missing empty lines
 - additional minor improvements

This closes #1002

This closes #1006

This closes #984

This closes #926.

-minor renaming
-improving JavaDocs

Closes #853

This closes #968

Also make sure that most tests run with enabled bloom filters, to increase test coverage.