Implemented NDNTLV chunking according to spec by introduced markers
prefix_to_path prints non-alphanum characters, otherwise information about CCNTLV types, NDNTLV markers, chunknumbers and random data is lost
fixed conflict
fixed prefix_to_path not working with CCNTLV NFN (ignoring NameSegment type when USE_NFN)
ccnl_URItoPrefix allocates a new chunknum instead of using the address of the argument
ccnl_prefix_dup copies chunknum