don't catch the exception thrown when we cannot obtain the testable mode lock, this is no longer necessary as all threads will obtain the lock at the beginning

excluded some more assert-like exceptions from coverage report and changed one into an actual assert

reduced the timeout for stall detection of testable mode to 1s, which should be perfectly long enough

refactored a type if-then-else monster into a for_each loop and exlcuded a pure cout function from the converage report

fixed bug that using poll-type transfers in testable mode could sometimes lead to stalled tests or assert failures.

Relaxed the schema a bit: variables are now also allowed directly on the application level and directories and variables may be mixed in arbitrary order. Also added 64 bit integer types.

- clarified some comments

added move-assignment operators for the accessors, which is required to use move-assignment operators of modules containing accessors