LOW: updated locales for GeomEdit
MEDIUM: Improved computation of halfplane and arcs (not perfect but
better)
MEDIUM: Anchor area has been improved so that the angle between the
orientation and the tangent of the rounded corner is always less than 45
degrees
LOW: Attempt to avoid union area with a single object
MEDIUM: Implemented Arch (CHORD) drawing
LOW: Slight improvement on substraction area of a union area
LOW: Added test for intersection of halfplane and arc
LOW: intersect arc and half-plane when line is tangent to arc