Added special treatment for line-line intersections.
Package multido is not required.
Added rule for german documentation.
Adjusted the 'veryclean' rule.
Renamed the option 'isectstart' to 'istart', and 'isectstop' to 'istop'.
Extended the \psshowcurve macro to use 'tstart', 'tstop', 'istart' and 'istop' for both Bezier curves and paths.