added some unit tests and changed all thread creations to use concurrent
execution of tasks using a threadpool

Change-Id: Ia17cb3c72d9367e7d4f9556b80c03ff038cff117
Signed-off-by: Alexander Wert <alexander.wert@sap.com>
forgot some files with the previous commit

Change-Id: Iae4640a7c6026c9cefcb7d7fc5440de6e3564f1a
Signed-off-by: Alexander Wert <alexander.wert@sap.com>
Merge pull request #52 from AlexanderWert/master

merge