Disallow AutoSelect on dangerous commands.

Commands flagged with NoAutoSelect will not auto select, even if the user has asked for it.  This is used for Cut and 3 different kinds of delete.  We later might extend it to fades and repair.

src/commands/CommandFlag.h

@@ -56,6 +56,7 @@ enum CommandFlag : unsigned long long
    HasWaveDataFlag       = 0x800000000ULL, // jkc
    PlayableTracksExistFlag = 0x1000000000ULL,
    AudioTracksSelectedFlag = 0x2000000000ULL,
+   NoAutoSelect            = 0x4000000000ULL, // jkc
 
    NoFlagsSpecifed        = ~0ULL
 };

src/commands/CommandManager.cpp

@@ -1336,8 +1336,11 @@ bool CommandManager::HandleCommandEntry(const CommandListEntry * entry,
       // NB: The call may have the side effect of changing flags.
       bool allowed = proj->ReportIfActionNotAllowed( 
          NiceName, flags, entry->flags, combinedMask );
+      // If the function was disallowed, it STILL should count as having been
+      // handled (by doing nothing or by telling the user of the problem).
+      // Otherwise we may get other handlers having a go at obeying the command.
       if (!allowed)
-         return false;
+         return true;
    }
 
    (*(entry->callback))(entry->index, evt);