remove getFile, use a new loadRaw instead
(cherry picked from commit 37953ea53dfa45c38cabee3c4ee51fcfce365e74)
add isPVR skeleton in wyUtils, update wyGLTexture2D to re-implement pvr support
(cherry picked from commit b313ec8ba81222a8bb8b9c7b7b990269c9f12b8f)