Added Background Images to the Title and GameOver Screens
Added Shop Music

-Edited Title Screen background
Merge remote-tracking branch 'origin/AddTitleGameOverBG' into ShopMusic
Added a "Not Enough Gold!" Notice In the Shop

- If a player attempts to purchase a ShopItem when he/she does not have enough gold, a notice will now pop up under the Shop Item
- Made the BuyItem method in Shop.cs accept a Button parameter so that the "Not Enough Gold" notice can be shown
- Made the Game Saved border appear above the ShopItem information. Before, it would display under ShopItem icons on the Z axis
Added Title Screen and Shop Music

-Removed the Mario Party song
-Reset PlayerHelpers so their Victim references would be set to null after a level ends
-Properly loaded the Strengthen Walls upgrade if the player has it
Merge remote-tracking branch 'origin/NotEnoughGoldNotice' into TitleShopMusic
Merge branch 'TitleShopMusic'