Make more comments accurate and follow style guide.
Give refund for unstarted, queued base facilities
Stop crashing on invalid save files

If a player, perhaps perversely, attempts to load a file with no YAML
nodes in it at all then the game crashes.

This fix replaces the crash with an error message.
Added Battlescape tooltips
Merge pull request #597 from cfailde/badsave

Stop crashing on invalid save files
Merge pull request #595 from cfailde/rs_comments

Make more comments accurate and follow style guide.
Merge pull request #596 from cfailde/refund

Give refund for unstarted, queued base facilities
- Fixed multiple rulesets resetting the starting base.
- Fixed extra strings from multiple rulesets not being properly combined.