make key generic
/
hook
add retry arg
cr edits
add another implicit
Merge pull request #21 from twitter/develop

Merge from twitter/storehaus
Merge branch 'develop' into memcache_mergeable_cas
gah fix merge
make kfn explicit
Merge pull request #252 from rubanm/memcache_mergeable_cas

Add hook for CAS based memcache mergeable