CBQE-931:CB(MB)ServerStandaloneInstaller never used

CouchbaseServerStandaloneInstaller and MembaseServerStandaloneInstaller
these classes are never used but...

they can be used and useful for running ep-engine as standalone server for unit testing

Change-Id: I5defc2c606ffe6fa12c2a2128e212cc368240450
Reviewed-on: http://review.couchbase.org/23911
Reviewed-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>
Tested-by: buildbot <build@couchbase.com>