Added more features for level design

Can set spawn and end points with colors
onWalk method triggers on tiles

Signed-off-by: James Hagborg <jameshagborg@gmail.com>
Added support for sound

Signed-off-by: James Hagborg <jameshagborg@gmail.com>
Added spikes and player death
Improved wall jumping

Jumping now pushes the player away from the wall
The player's velocity does not fall off as much while he is wall-jumping

Signed-off-by: James Hagborg <jameshagborg@gmail.com>
Added a dummy jump sound effect

Signed-off-by: James Hagborg <jameshagborg@gmail.com>