Pre-grasp state computation still not 100% working

[JenniferBuehler]

The pre-grasp state computation (grasp_planning_graspit::EigenGraspPlanner::getPregraspJointDOFs) is not working reliably yet. It just opens the hand completely in the cases I tested so far.
There are some problems with the GraspIt! methods Robot::autoGrasp() and Robot::quickOpen() and collisions being present (the latter being a "hack" of GraspIt!, but so far the only method with the functionality to open the hand until no contacts detected).

This issue needs more testing and probably a new method to replace the GraspIt! quickOpen().