Improved documentation.
Reorganized playtester.

For ConnectFour, Othello and TicTacToe.
Added helper for composite heuristics.
Changed HTML rendering in UIs.

Instead of writing HTML, the DOM API is used.
Mancala is still pending.
Also improved documentation.
Added support for heuristics and limited depth.

Agents can be specified with functions, by building an HeuristicPlayer.
Improved documentation.
New build.

Fixed some syntax mistakes.