MB-29153: Modify memcached audit event descriptions
MB-29153: Modify memcached audit event descriptions

"The named document..." used in the description of some memcached audit
events is potentially confusing as it implies the ability to "name" a
document to be audited.

Therefore the description of the following audit events is modified:
- document read
- document locked
- document modify
- document delete

Change-Id: I9e87108dd2d6ccbe4163a30a23c269f719e0b1c0
Reviewed-on: http://review.couchbase.org/92308
Reviewed-by: Dave Rigby <a09264da4832c7ff1d3bf1608a19f4b870f93750@couchbase.com>
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine