[FR] Named ssh connections

[gustaphe]

I think this is part of #118, but there are other issues in there that I don't think are necessarily connected.

I would like to be able to use named ssh connections instead of IP addresses. That is, these both work:

• Connecting to named connection via ssh remarkable-tether (defined in ~/.ssh/config)
• Using rMview with the related IP address (10.11.99.1)

Trying to supply remarkable-tether to rMview gives

ERROR] Could not connect to remarkable-tether: [Errno -2] Name or service not known
[INFO] Please check your remarkable is connected and retry.
[ERROR] [Errno -2] Name or service not known