This is a daemon that listens to "xilinx_xvc" (xilinx virtual cable) traffic and 
operates JTAG over serial.

Based on Felix Domke's work this xvc server uses serial port as output (because I'm cheap).

I've chosen the following connections:

TDI - RTS
TDO - CTS
TCK - TX
TMS - DTR

The daemon listens on port 2542, and multiplexes between multiple connections.