MB-12594: Added CMakeLists.txt; import changes as project has moved to github.com/couchbase

Change-Id: Ifffa735056d4d1f81cd7cf8a2c1237529ec6ec3b
Reviewed-on: http://review.couchbase.org/43005
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>