Rather than doing all the heavy lifting in live-build that nobody really
uses and which is quite inflexible, users should (in line with the syslinux
handling) either stick with the default grub configurations, or, supply
a custom one to live-build, rather than partial/single files only.
Previously, we needed to keep the lb_* prefix as the scripts
could also be executed standalone. Since the lb wrapper is
mandatory since squeeze, we can drop this now.
Daniel Baumann