Allow to execute any 'cbc-XXX' binary in PATH like 'cbc XXX'

Change-Id: I78ed98d27c95f49f24f83191b7bdc86e22c94e1e
Reviewed-on: http://review.couchbase.org/26784
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>