Update LICENSE and add license headers to CSS and JS in flink clients

Conflicts:
	LICENSE
	flink-dist/src/main/flink-bin/LICENSE
Split between source distribution license/notice and binary distribution license/notice.
Add a DEPENDENCIES file to list all maven dependencies with licenses and notices.

[ci skip]
[FLINK-1074] Fix for NULL input tuples in ProjectJoin
[FLINK-1075] Removed the AsynchronousPartialSorter.

This closes #104
[FLINK-1078] PrintingOutputFormat uses same partition indexing as FileOutputFormat.
[FLINK-1084] Fix broken links in "How to add an operator"
Disable merging of Iteration Aux Tasks

This will become obsolete once we have buffer oriented execution.
Disable it for now because it is causing a bug: FLINK-1087
Fix DeltaIteration Bug with Immutable Types

The CompactingHashTable did not obey the new serialization contract that
allows for immutable objects. We must always use the return value of the
deserialization methods and cannot assume that the data was put into the
reuse object.
Fix typo in package LICENSE