Remove the Staff List Widget, [roster] shortcode, and related user meta forms

[benlk]

Changes

• WIP

To Do

• Because the meta boxes used by the Staff List Widget and the [roster] shortcode are also used for bylines, specifically the "job title" meta and the "show_email" meta, we're going to have to figure out how Largo and this plugin interact. Who is responsible for providing the form?
  • I think this might work best if Largo keeps the complete form, but unregisters the plugin's corresponding form functions. The metadata would remain the same across both the theme and the plugin.
• Clean out tests for deprecated functions
• Deprecate functions that are no longer used in Largo

Why

Because we're pulling this functionality out of Largo as part of #1505 and https://github.com/INN/staff

[benlk]

This is not in the 0.6 milestone anymore.