status bar coordinates are now in meters
added a ruler to show measurements when creating polygons
updated polygon edit box to show values in meters and fixed a active point highlighting bug
highlight "snapped" points and made it possible to snap the first point
fixed a problem loading and saving interfaces
bool(QPoint(0,0)) was evaluating to False making it impossible to snap to points at (0,0)
method to return picklable version
added some ROS specific stuff