refactoring DateTimeUtils

it's not pretty but now it should be thread safe
MAJOR code rewriting and refactoring

removed some interfaces and therefore needed to remove a lot of methods
with removal of these methods some tests and other methods had to be commented out
this is all due to switching from soap to linked data

added event repository
linked in parts of code, some methods need to be implemented after merge of gabriels code

remodelled the connection model to resemble the ontology

ontology 0.1 should now be fully implemented