Documentation: last piace of Michael Clement's review
SimpleDesk: fix locking
SimpleDesk: fix releasing LTP values

When resetting universe, store the LTP values to separate hash,
then on the next run dump them tu universe, and forget them.

When something changes in the meantime, remove the value from reset hash.
QT5 Plugins - proper IID, removed json files

I believe the IID are supposed to follow java package notation. i.e. reverse domain + class/interface name.

JSON files are not used at the moment, so I removed them.
The point is to get some data about the plugin without actually loading it; for plugins
we need to list the ports, and for that we need to load the plugin anyway.
Fix unit tests: it seems that qt5 doesn't like empty language files.