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
Refactor collision resolution to its own method
Document and further refactor world2
Use the unit's vx and vy properties for stepping them, don't calculate there
Fix a derp, add some nice numerical integration for steps.
Remove explosion on collision test.
Set numerical integration factor to 1, comment exactly what it does
Add blinking to geociites
implemented
updated jcli
added requirements file
Remove old world, move world2 -> world
Add stub for map
Refactor the GameTile to use a macro, so it's more easily pluggable. Close #32
Use Players list instead of hardcoding for two players (though the vs. text is still hardcoded...)
Fix hardcoded vs. list
Move gametile styling to gametile.scss
Merge branch 'feature-site' into develop
Merge branch 'develop' into feature-newworld
Fill in Map and Tile classes