GRADLE-902 Adds support for ANTLR v3 and v4.
Reconciled outdated dependencies.gradle with current version.
Allow for custom ANTLR arguments on task.
Removed explicit variable initialization.
Configure the antlr configuration to be used by default by all antlr tasks.
Added integration tests, still includes classpath wrapping in mock build file.
Rework Antlr integration to not require a compile or runtime dependency on Antlr for Gradle.
Java build integration test added to Antlr 2 tests.
Updated Antlr plugin to use IncrementalTaskInputs.
remove unused logger field
share some more logic between versioned Antlr plugins
add some coverage for IncrementalAntlrTask
mention Rob in release notes
update antlr plugin userguide chapter
mention more antlr related changes in release notes
Fix handling of antlr grammar in nested folders

- some cleanup in IncrementalAntlrTaskIntegrationTest
- move SamplesAntlrIntegrationTest into antlr subproject
- rename AntlrPluginGoodBehaviourTest to AntlrPluginIntegrationTest
minor tweak to release notes