S4-66 Force application class to be defined when building s4r package
S4-66 Remove generatedS4R option from s4 deploy task, in order to simplify commands
S4-66 Check that appClass extends App

Patch by Aimee Cheng
S4-66 Check for indirect extension of s4.App

In case of failure throw exception instead of stopping the process
Merge branch 'S4-66' into dev

Conflicts:
	subprojects/s4-core/src/test/java/org/apache/s4/deploy/TestAutomaticDeployment.java
	subprojects/s4-core/src/test/java/org/apache/s4/deploy/prodcon/TestProducerConsumer.java
	subprojects/s4-tools/src/main/java/org/apache/s4/tools/Deploy.java
	subprojects/s4-tools/src/main/resources/templates/build.gradle
	test-apps/consumer-app/build.gradle
	test-apps/producer-app/build.gradle
	test-apps/simple-deployable-app-1/build.gradle
	test-apps/twitter-adapter/build.gradle
	test-apps/twitter-counter/build.gradle