removing obsolete methods
adding dependency on editor-api module in intentions, using EditorCell from open api.
refactoring NodeSubstituteInfo
regenerating migration script for editor
Correcting actions language generator
removing null-icon
simplifying actions language generator
Merge remote-tracking branch 'origin/master' into multipleEditors

Conflicts:
	languages/languageDesign/editor/languageModels/actions.mps
Merge remote-tracking branch 'origin/master' into multipleEditors
Plugin: find usages shows MPS usages of java code (text is a dummy yet)
simplifying editor generator & regenerating some models
removing some weavings from editor generator
regenerating all editors
EnumMemberValueRefExpression added & used u SideTransformTagUtils to avoid unnecessary acces to strucuture model on loading StyleAttributes class
using getIcon() method from superclass
generating stable inner class names
rebuilding all editors
add canExecuteAction() in selection
move ClearSelection logic from Escape_Action to Selection
move ClearSelection logic back to Escape_Action (if selectionStackSize > 1)
remove Clear_Action from EditorComponent