Support for extra rules such as "overlines", "three and three" etc.

[chen-yingfa]

Specifically, should allow user to turn on extra rules that influence the determination of victory. I think we should at least support the following rules:

• Ban overlines: User can't win by creating line with more than 5 stones of the same color.
• Ban three and three: User can place a stone that create two unblocked three in a rows at the same time.
• Ban four and four: Similar to above, but no double unblocked four in a rows.