Figure out how or IF we need to make CAPI collection aware

The current capi replication used by xdcr is not collection aware.

As a consequence, they still used old pre cheshire-cat version of ns_server code, such as, ns_memcached:get_meta used to check revision and update_docs. There are other API's used by CAPI which might need to be collection aware.

This task is created to check if CAPI needs to be collection aware if so, identifying the work involved.