move some functions unrelated to rdoc replication out of...

... xdc_rdoc_replication_srv.erl to the separate module

Change-Id: I08a0420b872ab16335e672ae07e95aaee7914698
Reviewed-on: http://review.couchbase.org/41936
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
remove all methods unrelated to documents replication

... from capi_ddoc_replication_srv

Change-Id: I046fbc05d4c6bdd535ece784fabb59cc63510937
Reviewed-on: http://review.couchbase.org/41937
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
ns_couchdb_storage - module that contains storage related functions

... that will be executed on ns_couchdb node

Change-Id: I97f884809ea9550015d0f6874d4b59239a726c69
Reviewed-on: http://review.couchbase.org/41938
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
service that will be maintaining compaction tasks on ns_server

.. node after couch_task_status will be moved to ns_couchdb node

[alk@tut.by: changed compression to compaction]

Change-Id: Ibfa95a77c19a3245706fd1161b6276f25117034d
Reviewed-on: http://review.couchbase.org/42088
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>