Merge pull request #26 from Shriken/feature-newworld

Feature newworld
Add particle system structure.
Merge branch 'develop' into feature-particles
Add random chance for collisions to kill
Clean up render function
Add unit deaths
Add particle handling
Make explosions look like clouds of smoke, not holywood fireballs
Make explosions redder again
Update submodule
Merge branch 'feature-newworld' into develop
Merge branch 'feature-particles' into develop
updated jcli
Refactor world2 to be much more autonomous in generating events, units will usually generate events for things like velocity changes on their own

Additionally, units are refactored to use heading and speed instead of vx and vy