Fixes #85 #105 #106 - Logging app

Created the logging app with two entry points: start session and log action.
This methods are called through POST requests, and must be done by logged users.

If timestamp is not provided, server local time is attached.

A looger.js script is provided for new games. Game should base on game_base.html
template. This template provides the game_start() function which also initializes
the logger. After this initialization, log function may be call to register
game progress.