Pre all the reamining bytes of an entry
  Post an array of 
   1. A dict keyed by Tag with {'type':,'value':} where value is a string unless type is i
   2. A string of the remainder

def _bin_to_extra(extra_bytes):
  """Pre all the reamining bytes of an entry
  Post an array of 
   1. A dict keyed by Tag with {'type':,'value':} where value is a string unless type is i
   2. A string of the remainder
  """
  #global _bam_value_type
  extra = StringIO(extra_bytes)
  tags = {}
  rem = ''
  while extra.tell() < len(extra_bytes):
    tag = extra.read(2)
    val_type = extra.read(1)
    if val_type == 'Z':
      rem += tag+':'
      rem += val_type+':'
      p = re.compile('([!-~])')
      m = p.match(extra.read(1))
      vre = ''
      while m:
        vre += m.group(1)
        c = extra.read(1)
        #print c
        m = p.match(c)
      rem += vre+"\t"
      tags[tag] = TagDatum(val_type, vre)
      #tags[tag] = {'type':val_type,'value':vre}
    elif val_type == 'A':
      rem += tag+':'
      rem += val_type+':'
      vre = extra.read(1)
      rem += vre+"\t"      
      tags[tag] = TagDatum(val_type, vre)
      #tags[tag] = {'type':val_type,'value':vre}      
    elif val_type in _bam_value_type:
      rem += tag+':'
      rem += 'i'+':'
      val = struct.unpack(_bam_value_type[val_type][1],extra.read(_bam_value_type[val_type][0]))[0]
      rem += str(val)+"\t"
      tags[tag] = TagDatum(val_type, val)
      #tags[tag] = {'type':val_type,'value':val}
    elif val_type == 'B':
      sys.sterr.write("WARNING array not implmented\n")
      continue
      rem += tag+':'
      rem += val_type+':'
      array_type = _bam_value_type[extra.read(1)]
      element_count = struct.unpack('<I',extra.read(4))[0]
      array_bytes = extra.read(element_count*_bam_value_type[array_type][0])
      for by in [array_bytes[i:i+_bam_value_type[array_type][0]] for i in range(0,len(array_bytes),_bam_value_type[array_type][0])]:
        aval = struct.unpack(_bam_value_type[array_type][1],by)
  return [tags,rem.rstrip("\t")]