Markus' work and Martin's tests: new addMember that does exactly what addMember does. However, roles are activated in the session of the user to be added also in tg-auth. This means he does not have to log in to have a role activated which another Project Manager gave him.

git-svn-id: https://textgridlab.org/svn/textgrid/trunk/middleware/tgauth@5844 7c539038-3410-0410-b1ec-0f2a7bf1c452