Removed _TrueSkill™_ from all user output.

... and from the database/code too, to avoid legal issues.
Corrected a link in README_upgrade_from_193.md.
Store only hashes of QKEYs (fixes #1).
Corrected displaying players with no skills.
Corrected a bug - recomputing of all skills.

The skills were recomputed from scratch on every run. Now corrected,
only new games without skills are recomputed. Skills for each game are
saved in a single transaction.
Added *Top Player* to the overview page.
During setup, fall back on default config files.
Handle Unvanquished colours.
Just output the image anyway regardless of whether we can anti-alias it.
Rebranding.

There are still a lot of Tremstats & Tremulous specifics to fix.

Conflicts:
	README.md
	setup.sh
Properly strip out colour control sequences.
Add support for drill & leech; remove support for hovel.
Hack in support for level shots in WebP format.
Level shots: expand to 16:9, maintain aspect ratio, centre them.