Asynchronous assets loading

This release improves the loading time at the beginning of the game by using coroutines to asynchronously load assets.
It decreased the loading time on my computer from ~2.5 seconds to ~0.9 seconds.

First Release of Quilly's Adventure

Contains the basic game and all its functionality until the first boss fight. Following features are included:

• Loading Screen
• Menu Screen
• Intro Screen
• Game Screen with two maps
• Game Over Screen
• Combat System
• Skill System
• Trigger System
• Audio
• Android Control Widgets
• Save and Load System
• Level Up System
• Powerups
• Portals
• Tiled Map Editor support