[jnc_io_base] interpret 0-lengthed serial read on POSIX as EPIPE (broken pipe)
[jnc_io_base] interpret 0-lengthed serial read on POSIX as EPIPE (broken pipe)

when a USB serial port disconnects, select () marks fd as readable, but read ()
doesn't set any errno and simply returns 0 -- unlike on Windows, where
::Read fails upon disconnect of the opened port

vovkos/jancy,vovkos/jancy,vovkos/jancy,vovkos/jancy,vovkos/jancy