add util to detect polygon ring winding order
add util to detect polygon ring winding order

rosamcgee/tangram,xvilan/tangram,tangrams/tangram,DHaylock/tangram,zerebubuth/tangram,xvilan/tangram,zerebubuth/tangram,DHaylock/tangram,rosamcgee/tangram,TitoAgudelo/tangram,xvilan/tangram,rosamcgee/tangram,ceseale/tangram,taylorhxu/tangram,DHaylock/tangram,TitoAgudelo/tangram,ceseale/tangram,taylorhxu/tangram,zerebubuth/tangram,TitoAgudelo/tangram,tangrams/tangram,taylorhxu/tangram,ceseale/tangram