Cataclysm update

Besides updating to latest version, I've also added tileset support (requires SDL).

Should I have created two separate pull requests?
This won't work - it evaluates to nil if tiles are off, and you can't concat nil onto a string. Try this:

```ruby
if build.include? "enable-tiles"
  executable = "cataclysm"
else
  executable = "cataclysm-tiles"
end
```