allow to initialize config by pulling it from another node

we also need to create duplicate set of node related keys for the node
we are copying config to in order for calls like search_node to
work correctly
initial implementation of couchdb node with the copy of config

no config replication yet

Change-Id: I934f5cd8e601cf1a830af9a96b060777748f1762
config replication from ns_server node to couchdb node

Change-Id: Iae84c24bdb0cdecefaf0566b9c1459ae0b759109
make single_bucket_sup a parameter in ns_bucket_worker_sup

so the same supervisors can be reused for couchdb node

Change-Id: I8a753e5ec8cee5cfab6c581ba710e7d80d718b02
handle ns_server node rename on ns_couchdb node

Change-Id: I0212a061f9d4522a300c3cd7120679dbe0a9c14b
do not use couch_config from ns_config_default

since there will be no couch_config on ns_server node, use env variable
with default value instead

Change-Id: If4bc21d0f4bc2fef55be83e36aa7e70587a0cff8
make sure that modules for child nodes are loaded in the same order

... as for ns_server node

Change-Id: Iec5f19c11046506d18063932e8c312a40b17e675
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
wip:create view

Change-Id: I7ca90e672ca06410529006bca9dd15d703af55eb