Ensure big blind is always bigger than small blind

[JohnnyJayJay]

Currently it is allowed to start a game with the same value for big blind and small blind and this even happens automatically when you use a buy in of 100 chips (both default to 1 in this case). This causes issues with the stakes in the first round however, causing the game to immediately move on to the flop.
To fix this, custom inputs should be validated accordingly and the default minimum for big/small blind should be set to 2/1 instead of 1/1.