pause_undo_history and resume_undo_history commands

[neurocyte]

Add pause_undo_history and resume_undo_history commands so that you can write long command sequences without spamming the history with undo steps.

[PalanixYT]

vim insert mode counts as a single action and can be reverted interely by pressing u once.

By using these commands, that functionality could be imitated, depending on the implementation.

This would require for these commands to "squash" the undo history (maybe this might be a better name for these commands?) into a single entry in the history

[neurocyte]

This would require for these commands to "squash" the undo history (maybe this might be a better name for these commands?) into a single entry in the history

pause_undo_history will disable the automatic creation of undo history for each command executed. resume_undo_history will enable it again, and create an undo point if the buffer has changed. I think the names are ok.

[neurocyte]

vim insert mode counts as a single action and can be reverted interely by pressing u once.\n\nBy using these commands, that functionality could be imitated, depending on the implementation.

I think we should also add support for mode init and deinit commands for this. That way we won't have to add pause/unpause to every keybinding that enters or exits insert mode. That can be done with a different feature request.

I added #92