macosx specific zmalloc.c, uses malloc_size function in order to avoid to waste memory and time to put an additional header

shareobjectspoolsize implemented in reds.conf, in order to control the pool size when object sharing is on

RubyRedis: set TCP_NODELAY TCP socket option to to disable the neagle algorithm. Makes a huge difference under some OS, notably Linux

critical bug about glueoutputbuffers=yes fixed. Under load and with pipelining and clients disconnecting on the middle of the chat with the server, Redis could block. Now it's ok

psort.c/h added. This is a partial qsort implementation that Redis will use when SORT+LIMIT is requested

Warns if /proc/sys/vm/overcommit_memory is set to 0 on Linux. Also make sure to don't resize the hash tables while the child process is saving in order to avoid copy-on-write of memory pages