Generate chnroute.txt file using shell.
Usage: ./chnroute.sh [-l] [-m merge.txt] [output.txt]
-l: add local domain ip address
-m: merge file from merge.txt
-s: slient mode
output.txt: chnroute output file, default is 'chnroute.txt'
Greate thanks to clowwindy's work https://github.com/shadowsocks/ChinaDNS/#about-chnroute