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/simpleColor.vert

@@ -0,0 +1,20 @@
+
+uniform mat4 projMat;
+
+uniform vec2 texSizeInv;
+uniform vec2 translation;
+
+attribute vec2 position;
+attribute vec2 texCoord;
+attribute vec4 color;
+
+varying vec2 v_texCoord;
+varying vec4 v_color;
+
+void main()
+{
+	gl_Position = projMat * vec4(position + translation, 0, 1);
+
+	v_texCoord = texCoord * texSizeInv;
+	v_color = color;
+}