Don't need to keep that inside the file context.
Move Battle.expand into expand_fleet
Drop the temporary raw_data in fleet.
Store sizes as integers internally.

- This ensures that the "smaller" ships, i.e. those defined with a size
  towards the beginning of the size list, will be at the top.
Minor formatting fix.
Fix all the pathing issues.

- Core really shouldn't try to base off where the files are, and not to
  mention that is kinda clunky way to do that.
- Also moved those test files to a shorter path.
Some fun with speedsim.