b=16777

b=16777
r=adilger,robert

- fixes server side scalability issue which became visible with lru resize work landed.
It replcaes linear list of held locks on server with hash table from class_hash.c which improves lock find time drastically for case when one client holds ~limit of server locks (quite a big number for big servers) which is very possible if all clients are idle and one compiles kernel, etc.