Enhance the clean script

(cherry picked from commit 4907fc9)

Author: niusmallnan

scripts/clean

@@ -6,5 +6,6 @@ rm -rf build dist bin images/*/build state
 rm -rf ./scripts/images/openstack/dist
 rm -rf ./scripts/images/vmware/dist
 
-docker rmi $(docker images --format "{{.Repository}}:{{.Tag}}" | grep rancher) || true
-docker rmi $(docker images --filter dangling=true -q) ||true
+docker rmi $(docker images --format "{{.Repository}}:{{.Tag}}" | grep -E "rancher|openstack|kexec|os") || true
+docker rmi $(docker images --filter dangling=true -q) || true
+git clean -dxf