Added method to format nanoseconds into a npt string.  Changed g_try_malloc() calls to g_slice_new() per GStreamer developer suggestions.  Fixed problem parsing dtcp content-type where it was dividing into three strings where it should have only been 2.
Merge pull request #102 from cablelabs/npt-str-g-slice-dtcp-content-type

Added method to format nanoseconds into a npt string.  Changed g_try_mal...