Update 0.15 - Crits!

V0.15 is mostly about combat improvements.

What's new:

• Critical hit chance, initially 3% but can be upgraded by a new item guarded by a new boss
• D key to hold/defend position

• Area effect program to stun and damage enemies

• Credits box now fleshes to indicate insufficient credits (to shoot, destroy wall, mine etc.)
  
• Nicer animations for credits glyph
• Animated fog

• Most recently visited levels are now updated
• Enemies recover when not in combat mode
• Gold processing

• New boss area
• More credits on start - 100k
• Fixed couple of bugs on the way