ignore some useless files.
Add: listen a local port and forward UDP to server.
rm /server3.c /clent3.c && add .gitignore
Merge pull request #1 from gaoyifan/Coding

rm /server3.c /clent3.c && add .gitignore
some small changes.
Fix bugs caused by using struct asock for UDP.
1.rewrite server.c to improve consistency;2.fix some bugs.
Finish ForwardUDP function of server.c(so server.c finished)
Merge branch 'master' of github.com:Dronevery/MultiwaySwitch