Added burntime to the new 'after this' button

Now you will queue new commands with the 'after this' button right after
the queued command, if this is a burn or maneuver-command.
I also added a new optional parameter to the FormatDuration method to
'delete' the micro seconds for a time format string.
Merge remote-tracking branch 'origin/fc_mandelay_addition' into peppie23