Added MP4 duration extraction to ODIDMediaEngine.create_resource()

create_resource() will now instantiate a IsoFileContainerBox for a content
 file when the resource profile implies an MP4 container, extract the
 duration from the MovieHeaderBox, and expose time-seek capability on the
 resource.

Note: this logic presumes that time-range modifications are supported for
      both segmented and non-segmented MP4s. Currently only non-segmented
      MP4s are supported.

Tested with an odid tree containing B-AVC_MP4_MP_SD-05.MP4 (AVC_MP4_MP_SD),
 bbb_avc-main_720x576i50_2M_heaac51_48kHz_160kbps.mp4 (AVC_MP4_EU.0),
 and O-AVCMP4_BC15A-01.MP4 (AVC_MP4_BL_CIF15_AAC_520). Proper durations
 were extracted for the last two (B-AVC_MP4_MP_SD-05.MP4 is segmented).