* trx_toolkit/trx_sniff.py: support additional capture filter
* trx_toolkit/trx_sniff.py: support sniffing on multiple ports
* trx_toolkit/trx_sniff.py: add support for reading from PCAP file
* trx_toolkit/burst_gen.py: basic TRXD header version 1 support
* trx_toolkit/data_msg.py: legacy flag is only for version 0x00
* trx_toolkit/data_msg.py: introduce header coding version 0x01
* trx_toolkit/data_msg.py: implement header version coding