refactoring unit-tests: changing property names
adding remove hint query parameters availability check
Merge remote-tracking branch 'origin/master' into 3.0/multipleEditors
reverting incorrect modification
nullpointer corrected
fixing unit-tests
SUpporting add/remove context hints in CellModel_RefNodeList with unit-tests
Updating model persistence for all models changes in 3.0/multipleEditors branch
Merge remote-tracking branch 'origin/master' into 3.0/multipleEditors

Conflicts:
	languages/languageDesign/editor/generators/baseLanguage/templates/main@generator.mps
	languages/languageDesign/editor/languageModels/editor.mps
	languages/languageDesign/editor/languageModels/structure.mps
	languages/languageDesign/editor/languageModels/typesystem.mps
	languages/languageDesign/jetbrains.mps.lang.editor.multiple.extension.testLanguage/languageModels/editor.mps
	languages/languageDesign/jetbrains.mps.lang.editor.multiple.testLanguage/languageModels/editor.mps
	languages/languageDesign/jetbrains.mps.lang.editor.multiple.testLanguage/languageModels/structure.mps
	languages/languageDesign/jetbrains.mps.lang.editor.multiple.tests/models/jetbrains/mps/lang/editor/multiple/tests.mps
	testbench/solutions/jetbrains/mps/tests.mps