Option to hide the statusbar icon

[tbergeron]

Is your feature request related to a problem? Please describe.
The plugin adds a button in the statusbar which I never use and has been broken forever anyways as described here: #129

Describe the solution you'd like
Have a settings in the plugin settings page to toggle it on/off.

Describe alternatives you've considered
I currently use CSS to hide it: .plugin-editing-toolbar { display: none }