Auto rewrite integer overflow fixed. Thanks to Gaurav for finding it (see issue 602 on google code), and Pieter Noordhuis for tracing it.

prepareForShutdown() fixed for correctness regarding what to do with AOF and RDB persistence on exit.

Take a pointer to the relevant entry of the command table in the client structure. This is generally a more sounding design, simplifies a few functions prototype, and as a side effect fixes a bug related to the conversion of EXPIRE -1 to DEL: before of this fix Redis tried to convert it into an EXPIREAT in the AOF code, regardless of our rewrite of the command.

childrens -> children in INFO output field names. This is a backward incompatible change, but really a minimal one.

Slight adjustment in growth calculation.

INFO now contains the time (in usecs) needed to fork() in order to persist. The info is available in the stats section of INFO.

Eval command table fixed to return the keys arguments of the command. We use zunionInterGetKeys() as it ZUNION/ZINTER have exactly the same semantic with a prefixed number of keys followed by key names.

peak fragmentation ratio removed as it is a confusing field for users and trivial to compute at hand now that there is peak memory information in INFO output

save peak memory usage as statistic and show it in INFO. Also a new INFO field was added showing the fragmentation ratio using the peak memory info.

added minimal cluster section in INFO output. This is only useful to check if the instance is or not configured as a cluster node, all the other informations are accessible using the CLUSTER command.