Add "refresh" button

[mmikeww]

After not using Specter for a while, and then returning to the window, I often get this error message in red at the top middle:

"Session expired. Please refresh and try again"

And I guess the solution is to either: Right click->Reload or View->Reload

However, neither of those options are very intuitive to find. It would be nice to have a simple refresh circle button, maybe in the upper right corner next to the view toggles and settings button.