Move towards toplevel CMakeLists.txt
Move towards toplevel CMakeLists.txt

Change-Id: I2083e87192a796bad6573d991ce18d3bc6de8564
Reviewed-on: http://review.couchbase.org/28728
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>
Tested-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

membase/libvbucket,couchbase/libvbucket