A short info is logged on applying auto-value plugin.

The task group definition has also moved to the plugin itself avoiding code duplications.
A short info is logged on applying the integration-test plugin.
The querydsl-plugin/extension stub has been added.
Fixed some documentation issues.
Fixed some documentation issues.
Changed the task group of the integration-test plugin.
Fixed broken unit test.
Added first functional version of the querydsl plugin.
The init task of the auto value plugin has been simplified.
The querydsl now also registers its created sources dir at the compileJava task.