Resolved POST issue.
Added a few features. Now the game ends when a player has won.

 - We now have a start page.
 - You can tell the computer to start.
 - Game ends when one player has won.
Reorganized the code. Computer can now make the first move.

 - Handler.Helper module provides functions to build parts of the pages that
   are needed often like the SVG for the field. Ideally, most of this should
   be moved to a template file.
 - GameLogic.Interaction needed to be changed because the computer can now
   make the first move.