Move moxi under cmake

Change-Id: I0abc72083af6937b20a5d8bea2d643a3767cdc96
Reviewed-on: http://review.couchbase.org/32335
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>
Reviewed-by: Nimish Gupta <nimish@couchbase.com>
Reviewed-by: Steve Yen <steve.yen@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>