GPUstate :Add  getTextureWidth() & getTextureHeight()

 and
Add texture level parameter
Add getWeightMask()
Use getUVGenMode()
Fix readIndexedTex() to use texture level for width/height
Fix typo
Merge pull request #3005 from raven02/getwh

GPUstate :Add getTextureWidth(int level) & getTextureHeight(int level)