allow debug mode to toggle

[andrewpbray]

@jimjam-slam What are your thoughts about expanding debug-mode to allow

• debug: false (the default)
• debug: toggle (on keypress would toggle on or off)
• debug-mode: true permanently puts on the debug class

?

Is "debug-mode" the right name for this? You can also imagine it as "author-view" or something. We could also add the values that the ojs variables take.

[jimjam-slam]

I'd be happy with the three values! I'd also love to include the OJS variables (we already have them on a few demos)... I'm not 100% sure whether the OJS engine is initialised if the user isn't using OJS, but if it's being a debug flag, I'm not too stressed about forcing it to be initialised.

[jimjam-slam]

No strong view on the name!