Drop deprecated code
Treat empty files as invalid input as it's not a valid xml anyway. Merge facility empties 'generated' file on conflict, and an attempt to read empty file leads to a warning which is of no real help in this case.
Generator: generated templates do not handle switch arguments.
core.properties language: constraints aspect serves as a mere utility model container
LanguageRuntime: towards classloading directly from generated code, to avoid SModule dependency for packaged languages (though SModule is ok for interpreted aspects)
LanguageRuntime: refactor uses of aspect descriptors to access through generic interface.
LanguageRuntime: update language descriptor templates to instantiate aspects directly (not through reflection in the base class). Sort aspect models to keep the order consistent
As there's code that assumes non-null aspects even for missing aspect models, fall-back to compatibility mode and delegate to old methods.
LanguageRuntime: regenerated all language descriptors with updated templates that instantiate all aspects directly  (not through reflection in the base class)
LanguageRuntime: drop InterpretedLanguageAspectsRegistry that ensured support of pre-MPS3.0 models.
core.properties language: update build script to include new location of utility model
LanguageRuntime: regenerated language descriptor for packaged language (drop implicit dependency in class file to a class that no longer exists).