MPS-20685 [build:MPS-135.1415] java.lang.IllegalArgumentException : Argument 0 for @NotNull parameter of com/intellij/openapi/actionSystem/KeyboardShortcut.<init> must not be null: Argument 0 for @NotNull parameter of com/intellij/openapi/actionSystem/KeyboardShortcut.<init> must not be null
MPS-20558 Focus is lost after adding node cell layout in concept editor
- merging UpdaterImpl & CommandContextImpl
- extracting UpdaterModelListenersController into a separate class
- simplifying Updater API
- cleaning collected events list on complete editor update
Merge remote-tracking branch 'origin/master' into 3.2/editorBugfixes
Merge remote-tracking branch 'origin/master' into 3.2/editorBugfixes

Conflicts:
	languages/languageDesign/editor/generator/source_gen/jetbrains/mps/lang/editor/generator/baseLanguage/template/main/trace.info
	languages/languageDesign/editor/source_gen/jetbrains/mps/lang/editor/behavior/CellKeyMapItem_Behavior.java
	languages/languageDesign/editor/source_gen/jetbrains/mps/lang/editor/behavior/CellKeyMapKeystroke_Behavior.java
	languages/languageDesign/editor/source_gen/jetbrains/mps/lang/editor/behavior/trace.info
correcting null-pointer
regenerating..
Merge remote-tracking branch 'origin/master' into 3.2/editorBugfixes