SIGSEGV handler refactored so that we can reuse stack trace and current client logging functionalities in other contexts.
remove disk-store related comments
declare hashDictType as external too
use server.unixtime instead of time(NULL) where possible (cluster.c not checked though)
fix time() instead of mstime() in expireIfNeeded
fix typo
Redis software watchdog.
Correctly set the SIGARLM timer for the software watchdog.
Mask SIGALRM everything but in the main thread.

This is required to ensure that the signal will be delivered to the main
thread when the watchdog timer expires.
Produce the watchlog warning log in a way that is safer from a signal handler. Fix a memory leak in the backtrace generation function.
define zlibc_free() in a way that is not shadowed by jemalloc.
Redis test: regexp to check if valgrind reported errors modified. Now we no longer look at the total count because this includes "possibly lost" bytes that are not interesting for Redis (tons of false positives because of how sds.c works).
Log from signal handlers is now safer.
Fixes for redisLogFromHandler().
added redis.sha1hex(string) as lua scripting function.

(The original implementation was modified by @antirez to conform Redis
coding standards.)
Test for redis.sha1hex().
Fix for slaves chains. Force resync of slaves (simply disconnecting them)  when SLAVEOF turns a master into a slave.
Fixed typo in comment: "te" -> "the".
Regression test for issue 417 (memory leak when replicating to DB with id >= 10)
Fixed a memory leak with replication

occurs when two or more dbs are replicated and at least one of them is >db10