PSSH parser ignores box version

[joeyparrish]

The PSSH parser in lib/util/pssh.js should skip any box with an unrecognized version number. It should skip the entire box, not the data payload.

[joeyparrish]

From ISO 23001-7 2nd edition:

aligned(8) class ProtectionSystemSpecificHeaderBox extends FullBox(‘pssh’, version, flags=0)
{
  unsigned int(8)[16] SystemID;
  if (version > 0) {
    unsigned int(32) KID_count;
    {
      unsigned int(8)[16] KID; 
    } [KID_count];
  }
  unsigned int(32) DataSize;
  unsigned int(8)[DataSize] Data; 
}

The generic CENC PSSH box is specified as requiring version=1 (see http://www.w3.org/TR/encrypted-media/cenc-format.html section 4)