Modify withSpinner.R to allow type=0

[sTeamTraen]

Hi - I hope I've done this right.

This didn't need many changes:

• Allowed a range of 0:8 instead of 1:8 for type.
• Made the "Loading" message conditional on their being a spinner (i.e., "type=0" is completely silent; I guess this is a question of taste and design philosophy).
• Removed what seemed to be an unnecessary sprintf() for the load of fallback.css (as I was working my way through the code trying to understand it).
• Added load0.css to avoid a runtime error in the browser console.

Thanks for reading, Nick