Changed film_grain.frag from using GLSL 1.2 with GL_EXT_gpu_shader4 t…

…o GLSL 1.3. The functionality required (bitwise operators) is present in this version whereas in the present it required the extension.

Some AMD cards did nor support the extension, which led to the game freezing on the Mojang splash screen with no error thrown or clear indication as to what caused it. This issue affected versions 154 and 155.
Closes #510.

src/main/resources/assets/botania/shader/film_grain.frag

@@ -1,5 +1,4 @@
-#version 120
-#extension GL_EXT_gpu_shader4 : enable
+#version 130
 
 uniform sampler2D bgl_RenderedTexture;
 uniform int time; // Passed in, see ShaderHelper.java