[Feature] Use Dropdown for Changing Gist Visibility After Creation

[ghost]

Right now to toggle a gist's visibility you must cycle through the options in a tedious way.

Example for switching an unlisted gist to public:

1. Open the gist
2. Click Edit
3. Click Make private
4. Click Edit (again)
5. Click Make public

Would be more convenient if this button (Make public|unlisted|private) was a drop-down to switch between the 3 modes in the Edit screen.

[jolheiser]

I think we could make this button the same as the one on the initial creation screen, right?