Support "permanent" connections

[Michał Sawicz]

There are some use cases where it would be desirable to create a permanent "connection" between content sources and consumers.

Some that I could think of:
- a directory to put your ebooks in that Beru can look at
- an app syncing your photos online
- contact groups to give apps access to

My proposal is that, when applicable, the user could check a checkbox in the share UI to make a share permanent, and apps could then request data from their permanent shares on startup, or a registered helper could get notified on change.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Alberto Mardegan (mardy)]

For some use cases, it looks like a read-only access should be sufficient (and actually preferable), such as cases #1 and #3.
For the #2 (app syncing your online photos) write access would also be needed.

So, ideally, when granting permanent access to a location, it would be great if the developer can specify whether the access needs to be read only or read-write.