Tweaked constants a little
Can now swipe up/down to show/hide the menu
Made the lower/upper bound calculations for menu position be functions
Added a function to check if the menu slidy bit is within its bounds
The buttons in the menu now return to their bounds when out of them after swiping
Swiping now works again, setting the velocity to zero on dragEnd was causing a problem as dragEnd is fired as well as a swipe