histedit: replace @addhisteditaction with @action...
histedit: replace @addhisteditaction with @action
@action supports verbs, messages, priority, and internal
messages should be translated.
internal means the action should not be listed.
geteditcomment will construct the verbs list based on
@actions (prefering priority over non priority, otherwise
favoring verbs with short forms over verbs without).
