New MessageBoxAppender

[Henry Padilla]

Hey, I found a need for a MessageBoxAppender while coding so I whipped one 
up.

I even added support for [title] and [text] labels so you can format your 
message boxes from the logger.  If anything goes wrong it'll use the 
Application.ProductName and Application.ProductVersion in the title.

How do I submit this to the project?
Tom Padilla