Temporary fix so that the game keeps going

Dispose of screen in finish()
Merge branch 'develop' of https://github.com/SweatyReptile/loser.git into develop
Add vertical scrolling
If a time limit less than 0 is passed in, the level will be timer-less
Increase the amount of time a title screen appears for
Infinite scrolling screens

Tested with a MenuInfiniteScrollingLevelScreen
InfiniteScrollingLevelScreens can have entities

Issue with some positions
Entities are properly placed

However, due to the inaccuracy of floats, the slight offset builds up.
This can be seen by falling straight down for a while. The books slowly
move upwards until they are completely underneath the other chunk's
background.
InfiniteScrollingLevelScreens work with 2 or more chunks
Dummy Menu Screen
Add offsetY to offset the camera's position
Properly position platforms (plus player)
Update images used in dummy menu screen
Add strict downwards scrolling

Reposition some menu entities
Remove some old comments
Player starts facing right in menu screen
Add the option for vertical and/or horizontal borders in level screen
Borders in infinite scrolling screens are malfunctioning

To be continued
Round entity positions to preserve accuracy longer

Entity positions are still distorted after falling for a long distance,
but not as fast as before
Fix inaccuracy with floats and properly place entities that are at 0
Make getBody() a method of Entity