Added clear() method to bezier curves to reset their state.
Added method to prepend and append piecewise curves to piecewise curves.
Fixed error in using wrong class to determine the segment delta_t
Updated hyperellipse creator to create hyperellipse with any multiple of 4 curves.
Renamed hyperellipse to superellipse.
Changed interface to make it more consistent between circle and superellipse creator. Fixed #29.
Cleaned up superellipse creator method.
Changed the superellipse creation method to use the specified delta t for the segments.
Added tests for creating degenerate superellipses and fixed creator to be able to create them. Fixes issue #28.
Superellipse creator can now create any even number of segments.
Merge branch 'feature/Hyperellipse_Curve_Creator' into develop