Added support for a URI source on SpriteSheet
Added support for a URI source on SpriteSheet

Signed-off-by: Grant Skinner <59bd0a3ff43b32849b319e645d4798d8a5d1e889@gskinner.com>

8823-scholar/EaselJS,abouthiroppy/EaselJS,markknol/EaselTS,EricHodgins/EaselJS,ytiurin/EaselJS,kidaa/EaselJS,SpringRoll/EaselJS,bambalaus/EaselJS,kidaa/EaselJS,mientjan/weasel,johnv315/EaselJS,nbellowe/EaselJS,Teino1978-Corp/https-github.com-Teino1978-Corp-EaselJS,felipegtx/EaselJS,briesurrood/EaselJS,createjs-components/easeljs,zhengjiangbin/EaselJS,Teino1978-Corp/https-github.com-Teino1978-Corp-EaselJS,gitzxon/EaselJS,rhildred/abacus,ovcharik/EaselJS,CreateJS/EaselJS,johnv315/EaselJS,markknol/EaselTS,felipegtx/EaselJS,bambalaus/EaselJS,exsodus3249/EaselJS,speedlightconsulting/EaselJS,xushuwei202/EaselJS,mientjan/EaselTS,gitzxon/EaselJS,mientjan/EaselTS,ovcharik/EaselJS,SpringRoll/EaselJS,zhengjiangbin/EaselJS,rhildred/abacus,thinkerchan/EaselJS,thinkerchan/EaselJS,abouthiroppy/EaselJS,julianromera/EaselJS,andrew168/EaselJS,nbellowe/EaselJS,ebabel-eu/EaselJS,CreateJS/EaselJS,andrew168/EaselJS,ebabel-eu/EaselJS,speedlightconsulting/EaselJS,ytiurin/EaselJS,markknol/EaselTS,mientjan/weasel,exsodus3249/EaselJS,legendvijay/EaselJS,xushuwei202/EaselJS,julianromera/EaselJS,8823-scholar/EaselJS,EricHodgins/EaselJS,briesurrood/EaselJS,legendvijay/EaselJS