Squash CouchbaseSingleModuleBuild

We're done with the transition to CMake and have a top level
CMakeLists.txt that includes all of the projects.

Change-Id: I9a4e2d997587011813286136806ddabc925fda6b
Reviewed-on: http://review.couchbase.org/42884
Reviewed-by: Dave Rigby <daver@couchbase.com>
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>