added two test cases for issue #100

test_thread_msg_block_w_queue:
	demonstrates the behaviour described in issue #100
	and that it is solved by PR #569

test_thread_msg_block_wo_queue:
	demonstrates behaviour similar to the above but without
	a messge queue. This works with the current master, but
	breaks with PR #569
Merge pull request #691 from Lotterleben/test-569

added two test cases for issue #100