PGE v2.16

FIX Emscripten JS formatting in VS IDE (thanks Moros)
+"Headless" Mode
+DrawLineDecal()
+Mouse Button Constants
+Move Constructor for olc::Renderable
+Polar/Cartesian conversion for v2d_generic
+DrawRotatedStringDecal()/DrawRotatedStringPropDecal() (thanks Oso-Grande/Sopadeoso (PR #209))
=Using olc::Renderable for layer surface
+Major Mac and GLUT Update (thanks Mumflr)