Fixed many bugs, added new features

+ Added a simple spleef log (for example to find players easier abusing
the jackpot)
+ Added spectate point. Spectate with /spleef spectate <game>

* Renamed flag jackpotamount to entryfee

- Fixed a bug where every player in the winner team gets the full
jackpot prize
- Fixed a bug that the players inventory won't be restored on death