Fixed VM corruption due to child fclosing the VM file directly or indirectly calling exit(), now replaced with _exit() in all the sensible places. Masked a few signals from IO threads.

Fixed memory human style memory reporting, removed server.usedmemory, now zmalloc_used_memory() is used always.

Fixed a never experienced, theoretical bug that can actually happen in practice. Basically when a thread is working on a I/O Job we need to wait it to finish before to cancel the Job in vmCancelThreadedIOJob(), otherwise the thread may mess with an object that is being manipulated by the main thread as well.

Introduced a new log verbosity level, so now DEBUG is really for debugging. Refactored a bit maxmemory. When virtual memory is short in RAM free the objects freelist as well as swapping things out.

Fixed a minor bug in GETSET, now the SET part is not performed if the GET fails because the key does not contain a string value

SHUTDOWN now does the right thing when append only is on, that is, fsync instead to save the snapshot.

better handling of non blocking connect on redis-benchmark: EPIPE on read does not print an error message now

some change to redis-sha1.rb utility to make it more robust against non-meaningful changes in the dataset

Fixed daemonization when using kqueue/kevent. Now the server initialization is performed *after* the daemonization

use __attribute__ format in sdscatprintf() when the compiler is GCC. Fixed format bugs resulting from the new warnings.

INFO refactored. Stack trace on memory corruption now dumps the same information as the INFO command

log rebuilding, random refactoring, work in progress please wait for an OK commit before to use this version