8BitBoy 1.45 - Run forrest run!

This is maybe the most requested feature of 8BitBoy yet. Now it's finally added with much success. Hope you enjoy this new addition.

- Speed running, press ALT or X button to run
- New music in World 2, both indoor and outdoor
- New music in level selection / world map
- New music in World 4 (only inside)
- Tutorial after intro - learn the upwards shot and speed running!
- The Walking cactus can be woken with a shot
- Reduced waiting time before reloading game
- New dying animation
- Added water splash (+ lava and sand)
- A few new sound effects
- Boss world 1 - fixed wall bug
- Black crows "caws"
- Added power-up sounds
- Added grass to world 2