Implementation of the internals that make possible to terminate clients overcoming configured output buffer (soft and hard) limits.

Fix for hash table collision attack. We simply randomize hash table initialization value at startup time.

all the stack trace related functions are now in debug.c. Now Redis dumps registers and stack content on crash. Currently osx supported, adding Linux right now.

On crash print information about the current client (if any), command vector, and object associated to first argument assuming it is a key.

AOF fileds in the global server state, and define names, renamed with more consistent names. More work to do.

AOF fixes in the context of replicaiton (when AOF is used by slave) and CONFIG SET appendonly yes/no.

new counter in INFO output: rejected_connections with number of dropped connections because of maxclients limit reached.

Fixed command table for SETEX and PSETEX causing the expire time to be hashed by Redis cluster instead of the key.

New script timeout semantics and SCRIPT KILL implemented. SHUTDOWN NOSAVE and SHUTDOWN SAVE implemented.

Fixed issues with expire introduced with latest millisecond resolution feature. Many time_t were not converted to long long, and one time() call was not replaced with mstime().

high resolution expires API modified to use separated commands. AOF transation to PEXPIREAT of all the expire-style commands fixed.