first attempt to non blocking implementation of slave replication and SYNC bulk data download. Never compiled so far...

Now it is possible to use quoted strings in the redis.conf file accordingly to the sdssplitargs() function capabilities.

Do not update the LRU info on key lookup when we have a saving child. With this trivial change the additional memory used while saving with a background child in presence of many read operations is zero.

redis-cli in interactive mode now prints the time elapsed of the operation performed took more than half a second.

Revert "Function to compute RSS memory usage in a fast way, suitable to be called inside keys eviction loops"

This reverts commit 7d47ecd5.

Revert "Now maxmemory, VM, and everything else uses the fast RSS memory used estimation instead of raw memory reported by zmalloc(). This means that setting maxmemory to 2GB will really have the effect of using up to 2GB of memory."

This reverts commit a3e60027.

Now maxmemory, VM, and everything else uses the fast RSS memory used estimation instead of raw memory reported by zmalloc(). This means that setting maxmemory to 2GB will really have the effect of using up to 2GB of memory.

Function to compute RSS memory usage in a fast way, suitable to be called inside keys eviction loops

synchronous I/O networking functions originally used just for replication refactored in a file as generally useful, they are used in the cluster branch for MIGRATE.

Also, use tcmalloc functions explicitly via macros to prevent symbol
lookups to resolve to native malloc/free on OSX.

Make sure to reset the signal handler and deliver again the original crashing signal when dumping the stack trace. This will allow to dump the core if core dumping is enabled.