Update 0.1.8: Lasers, UI, balancing

Major update after a long days work.

• added chests to minimap
• made minimap make more sense
• moved the ammo display to under the healthbar
• nerfed enemy damage
• various shadow optimizations
• modified level generation in an attempt to build more open, larger levels
• mouse lock and option to enable/disable. disabled by default. this took half of today's allotted hours :(
• made an attempt at balancing artifacts
• added a couple laser weapons to play with
• added laser enemies, with a cool telegraph effect