autoBackdrop with tuning

I use the Backdrop node to label my nuke scripts with a random color and when I do the color is always mustard or purple! Until I fixed the problem to a true random color selection.

I have made small changes to the default autoBackdrop.py script for the color selection when the node is used.

Also have added a message box asking for the label name before the Backdrop node is created. Faster than manually changing the name in the properties bin.

If you have any suggestions to improve this I'll do my best to composite your ideas.