Fixes to the main menu in preparation for adding an Intro Level - the big screen in the top right is now a display for all selection choices on the main menu and "continue" is selected from the 3 smaller screens below it. Eventually this will separate "play game" (loads intro level) from "continue" (goes to level select screen).

Fixes to jump timing ("coyote time" is back - a window after leaving an edge where the player can still jump), and to dash/dash-jump stability eliminating some accidental-double-jump bugs.