* Made KMetaData thread-safe.
* Improved auto-syncing: let the resource manager sync every n seconds and use as little DBus calls as possible.
Also syncing is done in a background thread. This is not intensely tested yet and may expose the D-Bus threading problems. Not sure yet.
* Speedup:
- Do not merge when saving.
- Only merge (i.e. load data from the store) when properties are read. This makes saving very fast since data is only stored to the RDF repository but never read.
- Add and remove statements in one DBus (i.e. Nepomuk RDFRepository) call
* Added KMetaData speed test: added 1000 resources in 5 seconds. Much better than 100 in 30s, I think. ;)