removed usages of def

Part of the effort to cleanup DSL method signatures, see https://groups.google.com/forum/#!topic/job-dsl-plugin/2-iuHl4tidI. All usages of def will be removed to be able to activate the NoDef CodeNarc rule.
removed usages of def, moved some tests which did not test behaviour of WithXmlAction to a new test spec

Part of the effort to cleanup DSL method signatures, see https://groups.go
replaced usages of def by Object

Part of the effort to cleanup DSL method signatures, see https://groups.go
suppress warnings for certain usages of def

Part of the effort to cleanup DSL method signatures, see https://groups.go
activate NoDef CodeNarc rule

Part of the effort to cleanup DSL method signatures, see https://groups.go
added release notes entry
Merge branch 'no-def'

Conflicts:
	docs/Home.md