Draft: Resolve "users cannot publicly share their dashboards"

Closes #112 (closed)

Grafana Users can create their own dashboards in their respective Project Organizations. However, they can not publicly share their dashboards, as they need elevated privileges to do that.

GF_USERS_EDITORS_CAN_ADMIN=true should fix this.

This only gives them admin rights for dashboard, dashboard folders and teams in their project.

How to test:

• fire it up
• create a thing
• log in with AAI
• view dashboard
• click on big blue Share button
• click on public dashboard
• accept the three check boxes and create public dashboard
  • can be revoked at any time