The major improvement of Luwrain API: Luwrain class no longer implies static behaviour

- core.Luwrain class has now regular (not static) members
- An instance of Luwrain class now replaces old application instances used as opaque objects
- Application.onLaunch() method now takes Luwrain class reference
- All corresponding fixes in the applications reflecting these changes
- DefaultControlEnvironment class now always takes the reference to Luwrain object

Minor fix:
- AppWrapperRegistry renamed to AppWrapperManager

TODO:
- core.Speech class shouldn't imply static behaviour as well
- AppWrappers should be renamed to AppShortcuts