This closes #1673.

Squashes the following commits:
- [tests] Wait for task managers in JobManagerFailsITCase
  Possible fix for: https://s3.amazonaws.com/archive.travis-ci.org/jobs/110235128/log.txt
- [tests] Move ITCase from runtime to tests
- [tests] Merge abstract and sub type class
- [tests] Determine JobManagerProcess ports from logs

This closes #1676.

- Remove Guava dependency
- Remove unused methods
- Move ZKString Serializer
- Add user-friendly error messages when parsing arguments

This closes #1623 and closes #1672

This closes #1663

This closes #1653

This closes #1650

They are not specific to RocksDB, just utilities for copying local
folders to/from HDFS. Moving them to flink-streaming-java means that
they are always in the classpath of the TaskManager, not only in the
user-code jar when using RocksDB. If they are only in the user-code jar
the external process runner cannot find the class files, leading to
ClassNotFoundExceptions.

This closes #1655

[FLINK-3413] [streaming] Make implicit conversions from Java DataStream to Scala DataStream explicit

This also clean up a lot of JavaDocs in various Scala DataStream API classes.

This closes #1642.

[FLINK-3401] [streaming] [api breaking] AscendingTimestampExtractor only logs violations of ascending timestamp order.

The user can also explicitly set an 'IgnoringHandler' or a 'FailingHandler', which do nothing on violations,
respectively fail hard.

 - one class handled periodic watermarks
 - the other class handled watermarks triggered by elements

This also makes sure that any timestamp assigner / watermark generators cannot generate
negative watermarks

This closes #1646

This adds dedicated WindowAssigners for processing time and event time.
timeWindow() and timeWindowAll() respect the TimeCharacteristic set
on the StreamExecutionEnvironment.

This will make the easy stuff easy, i.e. using time windows and quickly
switching the time characteristic. Users will then have the flexibility
to mix different kinds of window assigners in their job.

This also expands the translation tests to verify that the correct
window operators are instantiated.

[FLINK-3420] [api-breaking] Remove utility functions 'readTextFileWithValue' and 'readFileOfPrimitives' from StreamExecutionEnvironment

These methods are highly specific for very niche cases of bounded data stream processing.
As such, the disadvantages (bloat and lock the API, lock the development into support) outweigh the benefit.

This closes #1648

Because the implicit conversion creates a new ExecutionEnvironment, it leads to
strange errors when used withing programs with more than one source.

This closes #1563

This closes #1524

This closes #1635