Clear Linux VERSION and default exec driver.

Signed-off-by: James Hunt <james.o.hunt@intel.com>

VERSION

@@ -1 +1 @@
-1.9.1
+1.9.1-clear-containers

daemon/config_unix.go

@@ -13,7 +13,7 @@ import (
 var (
 	defaultPidFile = "/var/run/docker.pid"
 	defaultGraph   = "/var/lib/docker"
-	defaultExec    = "native"
+	defaultExec    = "clr"
 )
 
 // Config defines the configuration of a docker daemon.