High score improvements

[richtaur]

Make the following changes:

• Use memcache :[
• Only show each player once in the high score list (their highest score)
• Show the % of the highest score (eg, if first place is 100, then an 80 would be 80%)

[richtaur]

• Set cache to really high, like 24 hours
• Invalidate the cache when a new high score comes in

[richtaur]

Fixed by: https://github.com/lostdecade/play.lostdecadegames.com/commit/6f8ccdbbe7038eddc891f5a7e38aa9fd05cce728

And fuck the %, nontrivial and not worth it.