Bug 558642: SafeRunner can return results

SafeRunner has a second run method which expects a
ISafeRunnableWithResult<T>. The run method returns this result.
Also some refactoring of the handleException method has been done (boy
scout rule).

Furthermore test have been improved:
- adapt to lambda
- better test method names to recognize what was wrong
- better text messages in assertions

Change-Id: I3a648490f85101d87119335310c03774371408af
Signed-off-by: Marcus Hoepfner <marcus.hoepfner@sap.com>
3 files changed