CBQE-2466 ::  Enhancements:: test runner to store kv key, value, meta data read from memcached and compared in time

For a given kv store
- Store Meta Data information snapshot and compare it another time
- Compare active and replica meta data information. 

Use Case
- Static Analysis of Rebalance and failover tests

Sample Run

https://friendpaste.com/1ygRDPnsnH4bdvICqm7Bj2

Change-Id: I0c73ee55a73fdfe90fc1b7e9ae3666d066fd78b1
Reviewed-on: http://review.couchbase.org/43013
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>