Lua max exec time fixes: redisLog() to log the event moved before the lua_error() call that does a long jump so never returns. Aesthetic fixes in error message.

call the Lua hook with minor frequency. It is already enough to call it every 100000 istructions for near millisecond precision.

removed assert causing an illegal memory access. This was responsible of crashes during BLPOP and other list blocking operations.

Introduced a safe iterator interface that can be used to iterate while accessing the dictionary at the same time. Now the default interface is consireded unsafe and should be used only with dictNext()

when Redis fails accepting a new connection reports the error at WARNING and not VERBOSE error level. Thanks to offby1 for proposing this in the Redis mailing list. #backport-candidate

Fixed a bug with replication where SLAVEOF NO ONE caused a slave to close the connection with its slaves

This reverts commit 1b905277.
Moving all the new stuff in 2.4 branch.

This reverts commit c138dc7d.
Moving all the new stuff in 2.4 branch.

make sure that OBJECT ENCODING returns skiplist for sorted sets, and not raw, so that once we will merge specially encoded sorted sets everything will make sense.

fixed memory leak introduced with the previous commit. Many thanks to Pieter Noordhuis for spotting it in no time

Fixed issue #503. MONITOR + QUIT could crash the server, there are actually other interactions that could have the same effect (for instance Pub/Sub).