Undo: hide multi-dive-edit warning message on subsequent edit

When a different field is edited, hide any old multi-dive-edit
warning message. The reason is that we might want to add an "undo"
button to the message. But this will undo the wrong command if
we don't hide the message.

Sadly, this means that we can't use animated show / hide, because
an animatedHide() followed immediately by an animatedShow() does
not necessarily show the message. In other words, and animatedShow()
does not interupt a started animatedHide()!?

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

desktop-widgets/command_base.cpp

@@ -2,6 +2,7 @@
 
 #include "command_base.h"
 #include "core/qthelper.h" // for updateWindowTitle()
+#include "core/subsurface-qt/DiveListNotifier.h"
 
 namespace Command {
 
@@ -42,6 +43,7 @@ bool execute(Base *cmd)
 {
 	if (cmd->workToBeDone()) {
 		undoStack.push(cmd);
+		emit diveListNotifier.commandExecuted();
 		return true;
 	} else {
 		delete cmd;