Fix issue with non quadratic maps
Add console output to make it easier to spot mistakes caused by missing atlasses
Fix issue that player can move on tile beyond the map

stupid index wars, just let everything start with 1 -.-
Rewrite weird construct
Remove useless comments
Extend canvas's 2d context and add radiusOfSight

1. radiusOfSight is now a variable and can be set to whatever one
wants. Now it's 6 because that is what it was in the original game.
2. extend canvas by adding a method to draw with tiles instead of
indices as units