Bug 576377 - Provide shortcuts/commands for incremental
multiselection/multiple carets in text editors

Add various commands for multi-selection (intended for keyboard usage,
keyboard shortcuts are just suggestions):
- AddAllMatchesToMultiSelection (e.g. CTRL-ALT-SHIFT-J)
- AddNextMatchToMultiSelection (e.g. ALT-J)
- RemoveLastMatchFromMultiSelectionHandler (e.g. ALT-SHIFT-J)
- StopMultiSelectionHandler (e.g. ESC)

Change-Id: Id9add4daad15495ee00c76d8a5a7c5dc5608f506
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.text/+/191500
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Mickael Istria <mistria@redhat.com>
12 files changed