Allow games to be skipped with "Next game"

Current game ID is passed as an optional parameter when skipping a game
where it's your action. Skipped game ID's are stored in a session
variable and cleared when you return to the Overview page. Tests were
also updated.
Added Next Game link to the Game page

And added tests for it.
Fixed issue with failing test
Merge pull request #762 from AdmiralJota/253_complete_next_game_link

Complete next game link