New JPA model as JCR alternative
Extended document service test class and implemented delete flag functionality
* Added pre persist pre update
* Added jpa version of adding comments to a document.
* Changed testing env.
* Changed addComment.
* Added lazy loading of content collections.
* Adding comment to content works.
* Removed JCR Services.
* Fixed build scripts.
* CORS fixed.
* Added tagging service.
* Added new tag controller with paging functionality for tag list retrieval + integration test
* Added new comment service and repository
* Added access rights management
* Content: Exchanged @MappedSuperclass with TABLE_PER_CLASS strategy.
* Changed content fixture.
* Added remove function for access rights.
* Added subscription adding and removal functions.
Added comment service.
Merge remote-tracking branch 'origin/jpa' into jpa

Conflicts:
	ld-content/src/main/java/de/hska/ld/content/config/ContentConfig.java
	ld-content/src/main/java/de/hska/ld/content/service/CommentService.java
	ld-content/src/main/java/de/hska/ld/content/service/impl/CommentServiceImpl.java
	ld-content/src/main/java/de/hska/ld/content/service/impl/DocumentServiceImpl.java
* Added transactional to service methods.
* Fixed tag tests.
* Added reply to comment function.
* Added get documents page.