Added support of generated directory source for Intellij IDEA
Added support of generated directory source for Intellij tooling API
Added support of generated directory test source for Intellij tooling API and Gradle support
Merge branch 'feature/intellij-generated-source' of github.com:aliubimov/gradle into aliubimov-feature/intellij-generated-source
Just one property for generatedSourceDirs in IdeaModule.

Split and fix cross-version test this for this functionality
that is now correctly exposed in ToolingAPI.
Mention aliubimov's contribution
Merge branch 'aliubimov-feature/intellij-generated-source'