Added encryption algorithms options for SSH

[antenore]

Partly improve issue described in #1374

@dmauz This PR should also include the tunnel fixes. I hope it works

[dmauz]

Hi Antenore,

ssh over ssh-tunnel works now :-)
Greate Job!

I do not have an Paypal account, but I'll ask a friend to donate $ 100

best regards,
Dirk

[antenore]

Wow! Thanks!
We develop Remmina in our free (as in beer and as in freedom) time and use the money we get to keep the project alive (hosting mainly).
I hope, one day, we will have enough to hire someone to fix the most annoying Remmina bugs and missing features , so thanks a lot! You are building the next Remmina.

EDIT: Typo