Import modified Turtle Arena svn r2042 data files

Modified

- default.cfg (misc. cleanup to match arena-data)
- scripts/bots.txt, teaminfo.txt, and gameinfo.txt (use EBX character names)

Excluded Turtle Arena logo, players, player UI graphics, and bot chat.

- menu/art/titlebanner
- models/players/
- menu/art/char_*
- botfiles/bots/
Add placeholder PAKSUMS file
Add description.txt