Build

- When A3.h is removed from Command.h, other include files need to be
  added elsewhere.  That means the dependencies were wrong.  Hmm.

src/commands/CmdEdit.cpp

@@ -33,6 +33,7 @@
 #include <OldDuration.h>
 #include <Context.h>
 #include <Filter.h>
+#include <Nibbler.h>
 #include <i18n.h>
 #include <text.h>
 #include <util.h>

src/commands/Command.h

@@ -31,7 +31,6 @@
 #include <vector>
 #include <string>
 #include <Task.h>
-#include <A3.h>
 
 class Command
 {