The problem is that the module_property of csync are not really tight to
a context, but are global to all the contextes.
Which means csync_owncloud may still have a pointer to the destroyed
context of the destroyed folder.
By always resetting the context pointer, we make sure there is no stale
pointers there
To log to a different file for every sync.
This also changed a QueuedConnection to AutoConnection, that way we
directly save the log from the main thread in the file without waiting
for the event loop (so if it crashes before, the log has been writen)
Olivier Goffart