* Show connection errors for all failing accounts in the tooltip.
* Don't hide the 'service unavailable' state. We don't want intrusive
pop ups, but we don't want to pretend we're syncing when we aren't.
* Show sync-running icon also for SyncPrepare state. In my tests I
very rarely saw the sync-running icon before.
* Use a shared pointer to Account everywhere to ensure
the instance stays alive long enough for a sync to terminate
* Folder is now tied to an AccountState
* SyncEngine and OwncloudPropagator tie to an Account and use that
for all jobs they run
Issue: Since the setup wizard currently always replaces the
account, it will always wipe all folder definitions, even when
the actual changes to the account were minor.
This allows all the account state information to live in gui
while the sync-relevant data stays in libsync.
I also moved quotainfo to gui since it depends on the account state.
