Fix collision detection bug
Fix collision detection bug

- Rather than trashing the entity, change its `type` to `empty`. This
is still something I want to rework, but is good enough for now.
Deleting the entity caused all of the rows/cols to shift by one,
throwing the whole collision detection stuff off.
- Use `newCol` and `newRow` during `ghostify`. I’m unsure why this was
working before with `row` and `col` but don’t really care.

mattesja/mygame,stevenhauser/i-have-to-return-some-videotapes,mattesja/mygame,stevenhauser/i-have-to-return-some-videotapes