visualization of grid added
Merge branch 'ball-pivoting-SS13-group5' of https://github.com/happah-graphics/happah into ball-pivoting-SS13-group5

Conflicts:
	happah/triangulators/RayCloudTriangulatorBPA.cpp
Merge branch 'ball-pivoting-SS13-group5' of https://github.com/happah-graphics/happah into ball-pivoting-SS13-group5
lineMesh of the grid added