centos: updated make file

- Use latest yad now built for epel 6 in koji
- Call setenforce 0 avoiding selinux issues while creating the live cd
- Use tee for writing the log so progress can be seen in the console

Change-Id: If2d798af84718640f273036c62002a122e286993
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>