Reduce shape vertex size to 8 floats

It is not at all clear whether this is an improvement or not

shader/lighting/cap.vert

@@ -1,5 +1,5 @@
 #version 450 core
-struct PosColNorm { vec4 pos; vec4 col; vec4 norm; };
+struct PosColNorm { vec4 pos; vec4 dummy; };
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 layout (std430, binding = 3) readonly buffer Data { PosColNorm data[]; };
 layout (std430, binding = 4) readonly buffer Indices { uint indices[]; };