Implement security

[vyruz1986]

Using HTTPS is not really viable since this will always be used on a local network, and getting a 'real' signed certificate is not possible for private IP addresses.
This means we should not allow the ETS WiFi AP to be an unsecured (Open) AP, since that will send passwords in cleartext to all connected clients.

We should be able to set the following security parameters (#16 needs to be implemented first):

• Flag to allow anonymous viewing of racedata (off course any 'anonymous' viewers will still need the wifi password)
• Set a 'admin' password (mandatory to change first time with default in place)
• Make firmware update (Implement firmware update via web UI #15) only accessible to admin users
• Make config page (Change configuration via web UI #16) only accessible to admin users