Update to 1.1

Version 1.1 contains quite a few fixes that we didn't have enough time to fix until the deadline.

Fixed restarting the bossfight multiple times, if you returned to the collider, also there was no message shown as you entered the fight.
Fixed some glitches regarding the red color flashes when hitting an enemy (it would sometimes be stuck on red)
Fixed enemies that were completely oblivous to being shot - you could just stay out of range (now the player will draw aggro as soon as they hit them)
Added a slight HP buff to the ShootingEnemy type to make the rapid fire cannon more viable.
Changed the default movement mode to relative (W moves the ship in the direction it is facing), and added an option to change it to absolute (W moves to the top of the screen, regardless of ship orientation etc.)

And another tiny update: There's now music for the menu screen a LPF when hitting pause, and some GUI scaling issues that we were dealing with earlier.