Remove the remaining bits of deprecated GL usage

The drawing is now completely shader based, which makes away
with all usage of the depracted matrix stack. This also allows
us to do things like simple translations and texture coordinate
translation directly instead of doing everything indirectly
through matrices.

Fixed vertex attributes ('vertexPointer()' etc) are also
replaced with user defined attribute arrays.

shader/plane.frag

@@ -0,0 +1,36 @@
+
+uniform sampler2D texture;
+
+uniform vec4 tone;
+
+uniform float opacity;
+uniform vec4 color;
+uniform vec4 flash;
+
+varying vec2 v_texCoord;
+
+const vec3 lumaF = { .299, .587, .114 };
+
+void main()
+{
+	/* Sample source color */
+	vec4 frag = texture2D(texture, v_texCoord);
+	
+	/* Apply gray */
+	const float luma = dot(frag.rgb, lumaF);
+	frag.rgb = mix(frag.rgb, vec3(luma), tone.w);
+	
+	/* Apply tone */
+	frag.rgb += tone.rgb;
+
+	/* Apply opacity */
+	frag.a *= opacity;
+	
+	/* Apply color */
+	frag.rgb = mix(frag.rgb, color.rgb, color.a);
+
+	/* Apply flash */
+	frag.rgb = mix(frag.rgb, flash.rgb, flash.a);
+	
+	gl_FragColor = frag;
+}