Merge pull request #1 from FreeRDP/gtk3

SSH fixes from giox069-gtk3
workaround - checkboxes on 2 columns
Merge branch 'master' of github.com:antenore/Remmina
Should fix \#314 - checkboxes on 2 columns
Fixes #316 - VNC plugin settings - scaler too small
Merge branch 'antenore-master' into gtk3

Fixes #314 #315 #316