refactor multi module maven structure and apply camunda guidelines
refactor multi module maven structure and apply camunda guidelines

* multi module can be build from root, clean hierarchical structure, fixes #7
* parent is now camunda-release, the spring-boot nature is added by bom reference, fixes #2
* formmating is now 2 spaces indent for whole project, fixes #6. Also added some comments in the readme for non editorconfig users

camunda/camunda-bpm-examples,ingorichtsmeier/camunda-bpm-examples,camunda/camunda-bpm-examples,ingorichtsmeier/camunda-bpm-examples,camunda/camunda-bpm-examples,camunda/camunda-bpm-examples,ingorichtsmeier/camunda-bpm-examples