Add "/etc/kernel" hooks to pve-kernel-* scripts

[aglarendil]

Hi

I know that grub2 and grub-pc are mostly Debian Squeeze features but 2.6.32 and 2.6.35 are either. So why would not we have pve-kernel-2.6.3* with following lines in installation scripts (example for postinst script from official Debian kernel 2.6.32-openvz-amd64 package):

if (-d "/etc/kernel/postinst.d") {
  print STDERR "Examining /etc/kernel/postinst.d.\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postinst.d") &&
            die "Failed to process /etc/kernel/postinst.d";
}

if (-d "/etc/kernel/postinst.d/$version") {
  print STDERR "Examining /etc/kernel/postinst.d/$version.\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postinst.d/$version") &&
            die "Failed to process /etc/kernel/postinst.d/$version";
}