GL: Added image format test.
GL: Added image format test.

LSBOSS/bgfx,jdryg/bgfx,bkaradzic/bgfx,mmicko/bgfx,cuavas/bgfx,LWJGL-CI/bgfx,septag/bgfx,v3n/bgfx,0-wiz-0/bgfx,Extrawurst/bgfx,cuavas/bgfx,emoon/bgfx,kondrak/bgfx,jpcy/bgfx,darkimage/bgfx,bkaradzic/bgfx,mcanthony/bgfx,LSBOSS/bgfx,BlueCrystalLabs/bgfx,LWJGL-CI/bgfx,attilaz/bgfx,sergeScherbakov/bgfx,marco-we/bgfx,jpcy/bgfx,mendsley/bgfx,janstk/bgfx,sergeScherbakov/bgfx,aonorin/bgfx,elmindreda/bgfx,jdryg/bgfx,MikePopoloski/bgfx,Vertexwahn/bgfx,mendsley/bgfx,jpcy/bgfx,fluffyfreak/bgfx,septag/bgfx,Synxis/bgfx,LWJGL-CI/bgfx,attilaz/bgfx,marco-we/bgfx,marco-we/bgfx,andr3wmac/bgfx,sergeScherbakov/bgfx,LWJGL-CI/bgfx,ocornut/bgfx,aonorin/bgfx,0-wiz-0/bgfx,Vertexwahn/bgfx,ktotheoz/bgfx,andr3wmac/bgfx,fluffyfreak/bgfx,elmindreda/bgfx,attilaz/bgfx,jdryg/bgfx,mcanthony/bgfx,darkimage/bgfx,Synxis/bgfx,Extrawurst/bgfx,cyndis/bgfx,janstk/bgfx,Extrawurst/bgfx,bkaradzic/bgfx,cyndis/bgfx,v3n/bgfx,v3n/bgfx,darkimage/bgfx,bkaradzic/bgfx,andr3wmac/bgfx,0-wiz-0/bgfx,BlueCrystalLabs/bgfx,kondrak/bgfx,septag/bgfx,mendsley/bgfx,ocornut/bgfx,fluffyfreak/bgfx,jdryg/bgfx,mmicko/bgfx,MikePopoloski/bgfx,emoon/bgfx,elmindreda/bgfx,mcanthony/bgfx,ocornut/bgfx,Synxis/bgfx,ktotheoz/bgfx,fluffyfreak/bgfx,Vertexwahn/bgfx,aonorin/bgfx,cyndis/bgfx,BlueCrystalLabs/bgfx,kondrak/bgfx,jpcy/bgfx,LSBOSS/bgfx,MikePopoloski/bgfx,ktotheoz/bgfx,emoon/bgfx,janstk/bgfx,cuavas/bgfx,mmicko/bgfx