Some extra features (cairo, ConnectAfter(), GtkSettings, etc)

I have promised you, to send you new features from visionect/gotk3.
Please review the code. Constructive critics are welcome ;)

Best
Miha 
This will need to be changed back to 'conformal'. You should be able to run this from your project root: `$ sed -i 's/visionect/conformal/g' `find -name *.go | xargs`` to fix.