Add a make target to reformat the code

The source code should be uniform to make it easy to navigate
through the code

Change-Id: Id25229af70280ef793884f6df8d34463f9fd9640
Reviewed-on: http://review.couchbase.org/28759
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>