Add simple JSON-Output of connected players and game stats

[Xasin]

First things first for the Web-Server: A simple JSON output of the status of currently connected players etc.

This relies on #25, so that needs to be done beforehand. Once it's completed we should:

• [x] Set up a Sinatra folder structure
• [x] Add a first base-class that can be hooked up to the Lasertag, and outputs raw JSON on appropriate URIs
• [x] Maybe add a first basic, somewhat fancy view of a table of connected players and their different informations, like battery, team, dead/not, etc.

[Xasin]

Closed by 93d21f6361dd741479d57cfe1cec1f58d74e8340