Fixes for Admin Area Access, AppSumo Boost Workspaces, and the 3.0 Plan Card

A round of fixes shipped on October 12 and 13:

• Admins can open activities from the Admin Area: an admin who also holds a participant or sponsor role in a space no longer sees “You do not have permission to view this activity.” when opening that space’s activities from the Admin Area.
• AppSumo Boost workspaces can add participants and admins again: after an update on October 12, Boost add-on workspaces were blocked from adding participants and admins. That’s fixed.
• Transaction fee on the 3.0 plan card: the plan card on the “Activate 3.0” page showed the transaction fee 100 times too high. It now shows the correct percentage.