Log Message:
Update sysutils/mklivecd to 0.7.

Changes:

* s/DEPENDS/BUILD_DEPENDS/ for grub and cdrecord.
* Don't use "j" flag in tar(1), it is not available on NetBSD 1.6.x,
 use "z" flag instead.
* Replace harcoded tar with @TAR@ in the scripts.
* s/.tbz/.tgz/g

Thanks to Raoul Bhoedjang for his comments in private email.