Updated the ebuild:
- Install game binary into /usr/games/bin (was /usr/games)
- Generate the upstream version number from the gentoo version number
- Fixed license names
- Fixed dependencies
- Call prepgamesdirs to adjust ownership and permissions of the installed files
- Added more keywords as flare is not limited to x86/amd64 [1]

This ebuild is also available in the arx-libertatis overlay [2] for now.

[1] http://packages.debian.org/sid/flare
[2] https://github.com/arx/ArxGentoo