Try to build snappy with cmake

Change-Id: Ib5a1fbddbfc556e14a7159dd44ca3cb83113dda4
Reviewed-on: http://review.couchbase.org/30234
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>