Update 1.5.7: Pig Discoverability

A quick update to celebrate the anniversary of Balloon Popping Pigs on Steam. This update focuses on putting a spotlight on where to unlock and purchase the pigs as it seems to be the most common issue.

- Added random pig selection by holding down when selecting a pig. - Added the pig unlock system to pick a pig as well as the pause menu where it originally was. - Modified shop icon of a pig sitting in a cart. - Modified unlocking a pig to return you to the store rather than the pause menu. - Modified a lot of the popup texts in game to appear beneath the pause menu rather than over it. - Fixed visiting the pig selection via the pause menu from unpausing the game if you backed out. - Fixed an issue that would prevent text from telling the player they did not have enough coins to buy a gift.