Implement the access rights of sharing a project between multiple curators.

[xstephen95x]

• Should there be an owner / viewers / editor ?
• Should any member of a project view the project as their own.

[slivingston]

for addressing this issue, follow the simple uniform access model:

• either a curator cannot access a project, or
• a curator is on a list of curators who have complete read, write access to the project.

[xstephen95x]

Functional in commit 4f74770b19cb803dc4d4fd1f75492a167dfeb065