Abuse filters for game joining

[zond]

A logged in user should be able to see and join games in the 'open-games' list, but only if:

• [x] No current member of the game has blacklisted the logged in user.
• [x] The logged in user hasn't blacklisted any current member of the game.
• [ ] The logged in user has donated equal or more than the pay wall of the game.
• [x] The logged in user isn't blacklisted/played games by more than the max hated level of the game.
• [x] The logged in user hasn't blacklisted/played games more than the max hater level of the game.

[zond]

Added parts in https://github.com/zond/diplicity/commit/fbb949e019b9f14df0d286888487df8fc8b62abd