Update cleanDirs() in MTPResponder test
[deviceinfo] remove Buteo::SyncDBusConnection from DeviceInfoProvider

Apparently Buteo::SyncDBusConnection exists to address QTBUG-11413.
However, analysis of the above bugreport indicates that there is
no bug and calling QDBusConnection::systemBus() before additional
threads are created, as msyncd already does, is enough to prevent
any race issues.
[tests] make StorageFactory_test compile and pass

Removed some obsolete test cases.
[tests] add testGetDevicePropValueAfterObjectInfoChanged()

This test case covers the bug fixed in 2bb60691:
 [storage] discard object's all cached properties on ObjectInfoChanged
Merge pull request #45 from xhaakon/update

Enable StorageFactory tests

This PR cleans up and enables a unittest suite that had fallen out of use.
It's installed as "storagefactory-test", not to be confused with the
fsstorageplugin unit tests which are installed as "storage-test".