Merge branch 'antenore-master' into gtk3

Fixes #314 #315 #316
Merge pull request #1 from FreeRDP/gtk3

All recent changes to Remmina gtk3
Merge pull request #317 from antenore/master

Scaler layout improvement - gtk_widget_set_margin_end
Merge remote-tracking branch 'upstream/gtk3' into gtk3
Remove unwanted gettext
Chenge text of preference
\#commitcomment-7689638 gtk_widget_set_margin_end not supported by older versions of GTK

gtk_widget_set_margin_end  substitued with gtk_widget_set_margin_right
Merge remote-tracking branch 'upstream/gtk3' into gtk3
Update translations .po files

Added new strings and merge Ubuntu's translations
from http://packages.ubuntu.com/trusty/translations/
gettext fixes
added missing gettext
.po updates
Merge branch 'gtk3' of github.com:giox069/Remmina into giox069-gtk3
Merge branch 'giox069-gtk3'