Support for network outages

[crespum]

When the client is disconnected from the server in a non-clean fashion, it shall keep receiving the messages from the Ground Station and save them in a .csv file. Furthermore, the cliente shall try to reconnect 3 times and if it succeeds, those messages shall be sent to the server.

[crespum]

Twisted has a native class that solves this problem: ReconnectingClientFactory although documentation says this is not working with endpoints.

[crespum]

Master branch implements now this factory. Twisted team is putting more efforts into connections via endpoints since they are more flexible, so as soon as they support reconnections branch endpoint-3 should be adapted and then merged with master.

The status for the native support of endpoint reconnections is detailed in Twisted ticket #4753.