Now that csync builds as C++, this will avoid having to implement
functionalities needed by csync mandatorily in csync itself.
This library is built as part of libocsync and symbols exported
through it.
This requires a relicense of Utility as LGPL. All classes moved into
this library from src/libsync will need to be relicensed as well.
* 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.
