worked on sound and changes on mouse input

Hey guys!

This time the change is quite small, but it certainly adds some impact to the game. The first thing of note is that I worked on the sound effects for the dragon. Thanks for @gabemcarvalho for suggesting it!

The second change, also sugested by @gabemcarvalho, is with the mouse input. Now you can change the active music lane based on the height of the mouse, so you don't have to worry about the positioning of the mouse being inside of the lane circle during the gameplay (you still have with menus).