LoadQueue updates
LoadQueue updates

- Fixed issue where loadNext would have a null loader
- Fixed issue where a null load type would not fail gracefully.

Signed-off-by: Lanny McNie <2c0f44aec5a2bb5f2df6034ea7e908f734065b92@gskinner.com>

tehvgg/PreloadJS,andrew168/PreloadJS,andrew168/PreloadJS,CreateJS/PreloadJS,sokeroner/PreloadJS,SpringRoll/PreloadJS,dmnsgn/PreloadJS,Teino1978-Corp/Teino1978-Corp-PreloadJS,cnbin/PreloadJS,Teino1978-Corp/Teino1978-Corp-PreloadJS,cnbin/PreloadJS,createjs-components/preloadjs,ebabel-eu/PreloadJS,CreateJS/PreloadJS,sokeroner/PreloadJS,tehvgg/PreloadJS,not-only-code/PreloadJS,SpringRoll/PreloadJS