Added requestAnimFrame for backwards compatibility until branch is released
Added requestAnimFrame for backwards compatibility until branch is released

--HG--
branch : feature/node-compat

sanyaade-teachings/engine,playcanvas/engine,guycalledfrank/engine,shinate/engine,RainsSoft/engine,MicroWorldwide/PlayCanvas,guycalledfrank/engine,sereepap2029/playcanvas,SuperStarPL/engine,3DGEOM/engine,horryq/engine-1,playcanvas/engine,H1Gdev/engine,RainsSoft/engine,SuperStarPL/engine,3DGEOM/engine,aidinabedi/playcanvas-engine,sanyaade-teachings/engine,maxwellalive/engine,sereepap2029/playcanvas,shinate/engine,H1Gdev/engine,nizihabi/engine,aidinabedi/playcanvas-engine,maxwellalive/engine,nizihabi/engine,3DGEOM/engine,horryq/engine-1,shinate/engine,nizihabi/engine,RainsSoft/engine,sereepap2029/playcanvas,MicroWorldwide/PlayCanvas,horryq/engine-1,SuperStarPL/engine,maxwellalive/engine,sanyaade-teachings/engine