JTextPane added to sidebar, glitch remains

Added the JTextPane to sidebar.  Even before this was added there was a
paint issue where the scoreboard and background of the game screen would
be painted to the sidebar every time the sidebar was
repainted/revalidated. I suspect it's arising from somewhere in the
Board class. Given that this occurs with the JTextArea as well, I think
it has to do with the sidebarPanel as a whole. Kept all the old code in
case we want to undo this.
JTextPane: No Glitch + More Thorough Commenting

Turns out the glitch only shows up on my machine so you guys should be
fine. Might be something we want to fix later since inconsistency
between machines is probably bad