Option to open scratch buffer in a vertical split

I typically prefer to work in vertical splits, so I wanted the ability to open a scratch buffer in a vertical split.

This adds a new parameter to ScratchBufferOpen(), which indicates split type. 0 is horizontal, 1 is vertical. It also creates a :Vscratch command, which sets the proper split type.

I'm totally new to Vim script, so there might be a better way to do this. However, what I did worked well for me.