Revert "Added wrappers for Hadoop functions"

This reverts commit 74dded1c2cb87c459be3444d1c7387bbc510e154.
[FLINK-1076] Extend Hadoop compatibility. Added wrappers for stand-alone Map, Reduce, and CombinableReduce functions.
[FLINK-1076] Return type determined via type extraction.
Added test cases.
Minor improvements and clean-ups.
[FLINK-1107] Hadoop Compatibility Layer documented

This closes #131
[FLINK-1076] Extended Hadoop Compatibility documentation to cover Hadoop functions
[FLINK-1136] Replaced Flink logo in web submission client
Added Flink logo to JobManager web interface.
Updated Run Example Quickstart screenshots
Removed old gradients and unused image files from submission client.

This closes #145.
[FLINK-1145] Fix incorrect getter / setter detection
Fixed missing logo in offline plan visualizer
[FLINK-1149] DataSource sets DOP to 1 for NonParallelInputs.
[FLINK-1150] Fix size estimate for FilterNode. Data size changes proportional to cardinality.

This closes #146
Simplify Pojo/Tuple/CaseClass comparator extractKeys() method

Also fixes a bug with Java/Scala interop: TupleTypeComparator was only checking
for nested Java Tuples and Pojos, not Scala Case classes.
[scala] Add missing operator IT Cases