IDEA-80056 multiple selections - squash merge from krasa/multiEdit
Merge remote-tracking branch 'krasa/multiEdit3' into multiEdit

Conflicts:
	platform/lang-impl/src/com/intellij/codeInsight/editorActions/moveUpDown/MoverWrapper.java
	platform/lang-impl/src/com/intellij/injected/editor/CaretModelWindow.java
	platform/platform-impl/src/com/intellij/openapi/editor/impl/CaretModelImpl.java
	platform/platform-impl/src/com/intellij/openapi/editor/impl/SelectionModelImpl.java
	platform/platform-impl/src/com/intellij/openapi/editor/textarea/TextComponentEditor.java
IDEA-80056 merging selections in the highlighter tree, removal of carets within.