networking related stuff moved into networking.c

moved more code

more work on layout of source code

SDS instantaneuos memory saving. By Pieter and Salvatore at VMware ;)

cleanly compiling again after the first split, now splitting it in more C files

moving more things around... work in progress

split replication code

splitting more

Sets split

Hash split

replication split

even more splitting

more splitting

minor change

long long to string conversion speedup applied in other places as well. Still the code has bugs, fixing right now...

A problem with replication with multiple slaves connectiong to a single master fixed. It was due to a typo, and reported on github by the user micmac. Also the copyright year fixed from many files.

Dump a backtrace on sigsegv/sigbus, original coded thanks to Diego Rosario Brogna, modified in order to work on different OSes and to enhance reliability