Move test fixtures classes in a subpackage
XD-778 - Fixed  not resolved in JobRepoTests and JobPluginTests
XD-779 Send notifications as serialized Java Objects
XD-784-work in progress
XD-784 - updated gradlew.bat
Fixed package tangle in spring-xd-dirt
Added null check to TupleToJsonStringConverter
XD-790 - Fixed System.exit() test issue
XD-793 Upgrade Spring Data Redis to 1.1 RC1