MB-5264: Remove bad XDCR checkpoint code
MB-5264: Remove bad XDCR checkpoint code

Removing code that tries to ensure all items persisted, but is in wrong
place (update local_doc instead of ensure_full_commit) and doesn't work
as intended as the stats it checks aren't reliable.

Change-Id: Ib2a9043e1827e0fd0582ce583d03d562a428ef08
Reviewed-on: http://review.couchbase.org/16979
Reviewed-by: Damien Katz <99e6b749acbfbe2a596df99e91d24d6e1fdbee00@couchbase.com>
Reviewed-by: Junyi Xie <cec9b1c9f34a8d92cba938f3f3364d5120580782@gmail.com>
Tested-by: Damien Katz <99e6b749acbfbe2a596df99e91d24d6e1fdbee00@couchbase.com>

mschoch/ns_server,mschoch/ns_server,pavel-blagodov/ns_server,pavel-blagodov/ns_server,t3rm1n4l/ns_server,daverigby/ns_server,membase/ns_server,ceejatec/ns_server,daverigby/ns_server,membase/ns_server,pavel-blagodov/ns_server,daverigby/ns_server,daverigby/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,daverigby/ns_server,mschoch/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,mschoch/ns_server,ceejatec/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,vzasade/ns_server,vzasade/ns_server,ceejatec/ns_server,mschoch/ns_server,nimishzynga/ns_server,vzasade/ns_server,nimishzynga/ns_server,vzasade/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,membase/ns_server,mschoch/ns_server