Fixed a shader related crash that occured if the following conditions were met:

- BBGE_BUILD_SHADERS defined
- Blur enabled in config
- Entering a "warplocalnode"-Node while taking damage

These conditions caused it to enable shader related code while taking the
screenshot for the warp transition, that caused a crash because the shader-
related gl*() function pointers were not initialzed, because the current
code never loads any shaders.

BBGE/Shader.h

@@ -47,4 +47,8 @@ protected:
 	int mode;
 	float vx, vy, vz, vw;
 	bool loaded;
+
+	static void staticInit();
+	static bool _wasInited;
+	static bool _useShaders;
 };