Removed unused GL specs from glext.
Removed unused GL specs from glext.

darkimage/bgfx,marco-we/bgfx,andr3wmac/bgfx,mmicko/bgfx,MikePopoloski/bgfx,elmindreda/bgfx,bkaradzic/bgfx,mmicko/bgfx,BlueCrystalLabs/bgfx,cuavas/bgfx,ocornut/bgfx,jdryg/bgfx,attilaz/bgfx,Extrawurst/bgfx,mendsley/bgfx,jpcy/bgfx,Extrawurst/bgfx,andr3wmac/bgfx,sergeScherbakov/bgfx,cuavas/bgfx,mcanthony/bgfx,bkaradzic/bgfx,LWJGL-CI/bgfx,darkimage/bgfx,BlueCrystalLabs/bgfx,Synxis/bgfx,v3n/bgfx,fluffyfreak/bgfx,sergeScherbakov/bgfx,darkimage/bgfx,janstk/bgfx,bkaradzic/bgfx,kondrak/bgfx,fluffyfreak/bgfx,ktotheoz/bgfx,LWJGL-CI/bgfx,emoon/bgfx,0-wiz-0/bgfx,emoon/bgfx,marco-we/bgfx,LSBOSS/bgfx,v3n/bgfx,Synxis/bgfx,cyndis/bgfx,BlueCrystalLabs/bgfx,ming4883/bgfx,jpcy/bgfx,cuavas/bgfx,LWJGL-CI/bgfx,ming4883/bgfx,mcanthony/bgfx,mmicko/bgfx,MikePopoloski/bgfx,kondrak/bgfx,Vertexwahn/bgfx,jpcy/bgfx,mcanthony/bgfx,ktotheoz/bgfx,jdryg/bgfx,sergeScherbakov/bgfx,marco-we/bgfx,LSBOSS/bgfx,ocornut/bgfx,septag/bgfx,janstk/bgfx,Synxis/bgfx,jdryg/bgfx,elmindreda/bgfx,attilaz/bgfx,MikePopoloski/bgfx,andr3wmac/bgfx,aonorin/bgfx,Vertexwahn/bgfx,bkaradzic/bgfx,LSBOSS/bgfx,fluffyfreak/bgfx,mendsley/bgfx,kondrak/bgfx,attilaz/bgfx,Extrawurst/bgfx,septag/bgfx,fluffyfreak/bgfx,jpcy/bgfx,cyndis/bgfx,elmindreda/bgfx,0-wiz-0/bgfx,ktotheoz/bgfx,septag/bgfx,Vertexwahn/bgfx,cyndis/bgfx,janstk/bgfx,LWJGL-CI/bgfx,aonorin/bgfx,0-wiz-0/bgfx,ming4883/bgfx,jdryg/bgfx,aonorin/bgfx,emoon/bgfx,mendsley/bgfx,ocornut/bgfx,v3n/bgfx