Including some changes into memcached

[Slawomir Pryczek]

Hey, can this change be included into the repo? 

https://github.com/memcached/memcached/pull/996

Also have a change made which we're using in the company for like 10 years which will traverse given slab using dirty reads and then remove all expired items (using proper locking so the data is read, then re-read using proper lock facilities if anything is found to be expired). This will add another command to memcached (plus more stats which will tell the user how many items were removed using normal memcached facilities and how many items were removed using this "manual" cleanup)

Is that something which you'd include? Added that a long time ago so probably need to make some changes for it to be compatible with slab rebalancer. Any locks i need to hold during a read so the memory isn't reclaimed by slab rebalance during read?

Thanks