Add a filter to allow editors access to plugin settings page

Hi there,

The plugin looks great. What I’m missing is the option to allow editors to access the settings page.
We have one editor that takes care of everything blog related. We want that person to be able to customize the settings page of PublishPress so that he can group people in groups and edit editorial metadata without bothering admins.

Would it be possible to add a filter so that we can change who sees the settings page?
Even better would be to have the option to choose which settings tabs. For example, ideally, I would want the editor to be able to see and modify the Metadata, Statuses and User Groups Settings page. But not the General and Calendar pages.