Remove allocation_stats from INFO

Redis 2.6 doesn't return this info any more.

Change-Id: I45453e1ba40c1087187cdd08c1b2c4f98b8452e2
Reviewed-on: https://gerrit.causes.com/18835
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Aiden Scandella <aiden@causes.com>
Support Redis 2.6.10 INFO command fully

I tried to keep the old INFO values where possible for
backward-compatibility's sake.

Change-Id: I1074d2b0576b6ab7f7fcaa9662aa4be84920e231
Reviewed-on: https://gerrit.causes.com/18836
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Aiden Scandella <aiden@causes.com>