Fix console output for clipping mode
Re-enable clipping for rayrend

* no longer ignore clipping parameter
vvBaseVector3::sub() should substract, not add

* this is also fixing ROI-resizing in vview
Enable headlight in deskvox-qt

* for headlight light position is set to viewer position
Bugfix vvRenderer::getEyePosition()

* instead of fixing functions output value pultiple times, fix the
  function itself
* return eye position in world coordinates, not eye coordinates
* fix all calls which manually adjust the coordinates from eye space
  to world space
Bugfix jumping headlight for vview

* replace random headlight-position with a fixed one
* place light on eye position