Clean up the addrmerge() function, which was over-complicated and contained a number of memory leaks. The changes include:
Clean up the addrmerge() function, which was over-complicated and
contained a number of memory leaks. The changes include:

 - Add a comment describing what addrmerge() does.
 - Deal with 0.0.0.0./::. or AF_LOCAL callers correctly.
 - Use rpcbind_get_conf() instead of getnetconfigent() so we don't
   have to remember to free the returned netconfig struct.
 - Make just one pass through the ifaddrs list; we can pick up a fallback
   interface address in the same pass as the netmask comparison.
 - Define and use SA2SIN* macros to avoid the need for loads of
   protocol-specific local variables.
 - Use mostly protocol-independent code for building the netbuf version
   of the address to be returned.
 - Use the common cleanup code for virtually all error and non-error
   cases, fixing a number of memory leaks.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase