[IP/TCPIP]
- Add a Next member to CONNECTION_ENDPOINT to allow multiple connections to be associated with a single address file while not overwriting pointers, dereferencing other people's connection objects, and causing horrific amounts of memory corruption
- Add several sanity checks to prevent this from happening again
- Don't try dereference address files and connection endpoints in the free functions; there should be none associated since r52083 (sanity checks ensure this)
- Don't hold an extra reference to the address file when creating a listener; this reference is implicit
- This should greatly increase reliability of activities that open lots of sockets such as web browsing and running servers on ROS
- This also fixes most issues of not releasing a server port when the listener is closed
svn path=/trunk/; revision=52086