Add an angle configuration tag

[mikebolt]

Add a tag with a name like "g-angle" that lets you configure the initial view angle of the cube (the cube.rotation.x, cube.rotation.y, and cube.rotation.z). An example usage of this tag might look like this:

<g-angle angle-x="50"/>

or this

<g-angle angle-x="0" angle-y="0" angle-z="90"/>

To me it makes more sense to use attributes, but another option would be to use nested tags like this:

<g-angle>
    <g-angle-x>0</g-angle-x>
    <g-angle-y>0</g-angle-y>
    <g-angle-z>0</g-angle-z>
</g-angle>

The advantage to using attributes is that you can only specify any given attribute once.