extend the mongodb datapool
  - add a base class for all mongodb entities
  - introduce Company, Application classes
  - add tests for mongodb classes
Conflicts:
	de.telekom.bmp/src/main/java/de/telekom/bmp/data/Datapool.java
	de.telekom.bmp/src/main/java/de/telekom/bmp/data/User.java
	de.telekom.bmp/src/main/java/de/telekom/bmp/data/UserRole.java