[BP]MB-7353: Move featured data into Stored Value class

Change-Id: Ibe3f5be109864a01b34d43be839a39c1f59c7b8f
Reviewed-on: http://review.couchbase.org/25276
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
[BP]MB-100: Remove some unused code from StoredValue

- Remove the sizeOf function in StoredValue

  This function is no longer neccessary since we removed the
  small data struct fromt he stored value class.

- Remove the unused getKeyValLength() function
- Remove the stored_value_type enum

Change-Id: I8986eba2572f251f9389f2ce8ee03fc390502b24
Reviewed-on: http://review.couchbase.org/25277
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
[BP]MB-7497: Remove min_data_age and queue_age_cap

Change-Id: I192ce59267cf304ea3642881ff5ebf8ba9ce543f
Reviewed-on: http://review.couchbase.org/25278
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
[BP]MB-7497: Remove dirtiness from stored value

Change-Id: Ie1e201469cf9d58aaf42c335e66c26bfa6ca7701
Reviewed-on: http://review.couchbase.org/25279
Reviewed-by: xiaoqin ma <maxiaoqin2005@gmail.com>
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>