This dissertation was accepted by the University of Augsburg for the degree of doctor juris in July 2013. The study takes into account statutory and case law available until the end of 2013. It would not have been possible to write this doctoral thesis without the help and support of people around me, to only some of whom I can give particular mention here. First and foremost I would like to express my heart-felt gratitude to my supervisor Prof. Dr. Christoph Ann for his continuous support of my PhD study, endless encouragement, patience, and scholarly input. He has always made himself available to clarify my doubts and has been willing to help me to move forward whenever I faced obstacles throughout the whole period of research. Under his constant and invaluable guidance I could successfully overcome many difficulties. For all these reasons and many more, I am eternally grateful. I would also like to sincerely thank Prof. Dr. Ulrich M. Gassner for his insightful critique and interest in my research and for being the second referee of this thesis.