Merge suggestion

Hi

While working with go-webkit2 I have found out that I need some features that are not present in sqs/gotk3.
This is why I have merged conformal/gotk3. I have also implemented some extra features and fixed few bugs by myself.
Anyway this version works with go-webkit2.
It works with one relay small change, signal API has changed a little with newer versions of gotk3.
Example (also the only file that needs to be changed in go-webkit2 :)  )
https://github.com/visionect/go-webkit2/blob/master/webkit2/webview_test.go

I suggest merge because I assume I am not the only one who is missing features present newer versions of gotk3 while working with go-webkit2.

Best
Miha