Updated to clipper library 5.1.4

Added functions:
"setDebug": set debug level, debug sends messages to console
"orientation": returns orientation of polygon
"minimum": shrink polygon, normally a triangle to put placemark in the middle
"clip": clip two polygons, all clipper cliptypes are supported
"clean": interface to clipper "CleanPolygons" function
"fixOrientation": fix orientation for inner and outer polygons
"simplify": interface to clipper "SimplifyPolygons" function