Add exists() and waitForX() to cdap-client classes
Addressed comments
Merge branch 'develop' of github.com:caskdata/cdap into feature/improve-client

Conflicts:
	cdap-client/src/main/java/co/cask/cdap/client/DatasetClient.java
	cdap-client/src/main/java/co/cask/cdap/client/DatasetModuleClient.java
	cdap-client/src/main/java/co/cask/cdap/client/DatasetTypeClient.java
Fixed sleepDelay bug in ProgramFlowUtil
Merge pull request #557 from caskdata/feature/improve-client

CDAP-398 Add exists() and waitForX() to cdap-client classes
Spark Integration: Streams support for Spark Jobs

Spark Integration: reactored
Spark Integration: Added readFromStream without time
Spark Integration: Fixed according to PR1
Spark Integration: Addressed comments of PR2
Spark with Streams unit tests
Spark Integration: Addressed PR3 comments
Spark Integration: Fixed function header
Spark Integration: Spark with streams unit test
Spark Integration: Fix logging string in AbstractSparkContext
Spark Integration: Fixed according to comments
Spark Integration: Remove ambiguous return false statement
fix incorrect usages of ByteBuffer.array()
better impl of Bytes.toString()
Merge pull request #564 from caskdata/feature/spark-streams

Spark Integration: Streams support for Spark Jobs
Merge branch 'feature/fix-bb-array' into develop