ModelDependencyManager refactored to be updated on model changes (added/removed languages/devkits) right away, without model listener.
The drawbacks of the listener are (a) models that doesn't send change notifications (canFireEvent()==false) but get imports updated (e.g. TransientSModel) doesn't get updated ModelDependencyManager (and hence dependant code, like Typesystem, fails to recongized changed scope); (b) model listener that uses MDM and is invoked prior to MDM own model listener would get stale cache.
MyModuleWatcher shall not unregister itself on the first change.
Building complete set of imports is quite cheap (tens of microseconds), KISS.
Organize imports
Merge remote-tracking branch 'origin/master' into 3.1/artem/ModelDepManager
remove not used classes
fix PersistenceTest
Merge branch '3.1/artem/ModelDepManager'