Added new file utils/net.py
Added new file utils/net.py

in_cksum() is an implementation of Internet Cheksum (RFC 1071)


git-svn-id: ee7a57951e762bd0bd73821a456cc95fa2e543d2@3212 1105ee14-b0fa-0310-85a5-ff3eed429ff7

umitproject/umpa,umitproject/umpa