(re)added support for EditListBox insertion (cvp2ri-431)

    IsoFileContainerBox.trim_to_time_range() now supports the removal of
     EditListBoxes from the source content binary and the (optional) insertion
     of EditListBoxes that represent the trimmed time range.

    Added supporting functions remove_edit_lists() and insert_edit_lists().

    The latter currently is implemented to create a "simple" EditListBox
     per track that maps directly to the content duration. There's a
     commented-out implementation that inserts an "empty edit", as
     suggested in DLNA Part 2. But I've experienced interoperability issues
     with both VLC and QuickTime players with empty edits.

    Tested this change with segmented and non-segmented DLNA reference MP4s
     with and without pre-existing EditListBoxes and with and without
     EditListBox insertion enabled using the odid-mp4-parser test interface.

    MCVT that were previously failing with a "Response does not include a
    'Elst' Box or it is not in correct position" now pass.