Creating a new virtual file and replacing a file with a virtual one now
have their own text in the protocol, not just "Downloaded".
To do this, the SyncFileItem type is kept as
ItemTypeVirtualFileDehydration for these actions. Added new code to
ensure the type isn't written to the database.
While looking at this, I've also added documentation on SyncFileItem's
_file, _renameTarget, _originalFile and destination() because some of
the semantics weren't clear.
Previously, there was csync_ftw_type_e and SyncFileItem::Type. Having
two enums lead to a bug where Type::Unknown == Type::File that went
unnoticed for a good while.
This patch keeps only a single enum.
This gets rid of the csync_statedb sqlite layer and use
the same code and same connection as the rest of the SyncEngine.
Missing functions are added to SyncJournalDb and change a few minor
things (like changing SyncJournalFileRecord::_modtime to be an int64
instead of a QDateTime, like it was in csync).