Added function to rotate point around a specific center
Added function to rotate point around a specific center

This function will rotate a point around a specified center. It is rotating in the cartesian pixel coordinates of the layer. Therefore, it may not preserve the radius on large rotations (I think).
arkhemlol/Leaflet.GeometryUtil,arkhemlol/Leaflet.GeometryUtil,makinacorpus/Leaflet.GeometryUtil,makinacorpus/Leaflet.GeometryUtil