Make it possible to delete revisions in the history dialog

bouquin/locales/en.json

@@ -22,7 +22,7 @@
     "key_changed_explanation": "The notebook was re-encrypted with the new key!",
     "error": "Error",
     "success": "Success",
-    "close": "Close",
+    "close": "&Close",
     "find": "Find",
     "file": "File",
     "locale": "Language",
@@ -81,8 +81,10 @@
     "find_bar_match_case": "Match case",
     "history_dialog_preview": "Preview",
     "history_dialog_diff": "Diff",
-    "history_dialog_revert_to_selected": "Revert to selected",
+    "history_dialog_revert_to_selected": "&Revert to selected",
     "history_dialog_revert_failed": "Revert failed",
+    "history_dialog_delete": "&Delete revision",
+    "history_dialog_delete_failed": "Could not delete revision",
     "key_prompt_enter_key": "Enter key",
     "lock_overlay_locked_due_to_inactivity": "Locked due to inactivity",
     "lock_overlay_unlock": "Unlock",