Allow webapp users to play against AI opponents

[karlmdavis]

This is needed for several reasons:

1. Will really help adoption, as users don't have to drag a friend into it.
2. It will be fun to implement.
3. It will lay some of the groundwork for AI-only tournaments, which I think would be really cool.

[karlmdavis]

Requirements:

1. A new game's "invite a player" section will have to be replaced with a dropdown that allows players to choose how a second player will be chosen. For now, the only two options will be "Invite A Friend" and "Play Against AI".
2. The "Play Against AI" option should have two sub-options: select a specific AI or a difficulty level.
   1. The control for selecting a specific AI should probably be combo box, as there may eventually be hundreds to choose from.
   2. The option to select a difficulty level should be the default sub-option, with the easiest one of the three (or so) selected as the default.
   3. The first release should only have the difficulty level option.
3. Once a game is started, play proceeds normally for the human player. The AI will not attempt to modify the number of rounds in the game.

Sizing:

• 2.0h: Create an IAiPlayer interface and "random idiot" implementation.
• 6.0h: Create a web service method that returns the list of available AI players. Calling this method will populate the DB, as necessary.
• 2.0h: Create a web service method that allows players to join an AI player to their game.
• 6.0h: Update the submitThrow(...) method in the web service to automatically request and record AI players' throws, if playing against AI.
• 6.0h: Rework the "invite an opponent" controls to allow selecting AI players.
• 2.0h: Add an IT that plays through a game with an AI opponent.
• 8.0h: Write a couple of more AI implementations, that correspond roughly to "medium" and "hard".
• 32.0h total

[karlmdavis]

As of commit 4fd9916, this is done.