NORSPEC-287 Make alpha sRGB correction curves match OpenGL spec.

.../newview/app_settings/shaders/class1/deferred/alphaF.glsl

...wview/app_settings/shaders/class1/deferred/materialF.glsl

...pp_settings/shaders/class1/deferred/multiPointLightF.glsl

...app_settings/shaders/class1/deferred/multiSpotLightF.glsl

...ngs/shaders/class1/deferred/postDeferredGammaCorrect.glsl

...ew/app_settings/shaders/class1/deferred/softenLightF.glsl

...ew/app_settings/shaders/class2/deferred/softenLightF.glsl

indra/newview/lldrawable.cpp