Use couchstore file API v4

Required to build against couchstore as of this change
http://review.couchbase.org/#/c/25605/2

Change-Id: I55c1ee959079abc5a23b517531b9cf9f9ea10d07
Reviewed-on: http://review.couchbase.org/25607
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Aaron Miller <apage43@ninjawhale.com>
MB-7435: Add tap producer stats that shows num of sent items per vb

Change-Id: Iccb666bdaf85d628305925b61a2a9e0cc975570c
Reviewed-on: http://review.couchbase.org/25243
Reviewed-by: Chiyoung Seo <chiyoung.seo@gmail.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
MB-7435: Add a command to get estimates of keys to move

Change-Id: I8c7dfd23dceed93c8533891128c6448b284aa02f
Reviewed-on: http://review.couchbase.org/25244
Reviewed-by: Chiyoung Seo <chiyoung.seo@gmail.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
MB-6368: Add force shutdown variable to stats.hh

This change is needed in order to reduce code dependencies in
couch kvstore. By reducing dependencies it will allow us to
write unit tests for couch kvstore and will also reduce
dependencies for multi-reader/writer changes.

Change-Id: I0c80938b8a3b5427b7a1c6ba0f8aea1bc8cf0475
Reviewed-on: http://review.couchbase.org/25478
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
MB-6368: Move EventuallyPersistentEngine refs out of kvstore

Change-Id: I8ad285d4f668ecbf85456d89f7028a15d97a928e
Reviewed-on: http://review.couchbase.org/25479
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
MB-100: Remove kvstore apis for getting shard information

These are no longer needed since we don't support sqlite anymore

Change-Id: I107316edc4425b3faf82eac78df8219ba54effbe
Reviewed-on: http://review.couchbase.org/25675
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
MB-7966: Change VBucketMap name from vbuckets to vbMap

Change-Id: I215871766f95142bde8a866d8a52d7d549d99def
Reviewed-on: http://review.couchbase.org/25692
Reviewed-by: Jin Lim <jin@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
MB-7735: Fix to a race in notifying / releasing TAP connections

Change-Id: I35deeeaab98235500d9ba22c213c413eac1fbc04