use sockets from pool for all compaction related calls to memcached

to be able to run compaction daemon on a node without ns_memcached
server

Change-Id: I193fd60957eaa973860452436bc63e2202c4082b
wip: runs on one node with one bucket without crashes

Change-Id: I12294c2d069dead2d18a5aac130ee65a876ca82f
wip: ddoc replication

Change-Id: Ied4b77e9fd3ed7f950fc686218ea754d39f0a8f9
loggers

Change-Id: If18e3169605f4fb01a2b42a36a3a9b8ecc28a43e
wip:two nodes, rebalance is still broken

Change-Id: I6e0689a5504903ef71617a3845cc5e159d4a2390
wip: rebalance works

Change-Id: I88eac6060422f44280a1f57d7a54468aaeda9fe5
wip: run memcached sockets pool on couchdb node

Change-Id: I5d937b4e3cd7f520d3949642f592a4604d08c2dd
wip: temporary stab for xdcr stats

Change-Id: I86f1b1cd6f67412b835af9ddd99e5b4d200699f9