Full backport of the autostart / autoboot rollup patch from
master to stable-1.0.

lxc-autostart: rework boot and group handling

This adds new functionality to lxc-autostart.

*) The -g / --groups option is multiple cummulative entry.
    This may be mixed freely with the previous comma separated
    group list convention.  Groups are processed in the
    order they first appear in the aggregated group list.

*) The NULL group may be specified in the group list using either a
    leading comma, a trailing comma, or an embedded comma.

*) Booting proceeds in order of the groups specified on the command line
    then ordered by lxc.start.order and name collalating sequence.

*) Default host bootup is now specified as "-g onboot," meaning that first
    the "onboot" group is booted and then any remaining enabled
    containers in the NULL group are booted.

*) Adds documentation to lxc-autostart for -g processing order and
    combinations.

*) Parameterizes bootgroups, options, and shutdown delay in init scripts
    and services.

*) Update the various init scripts to use lxc-autostart in a similar way.
Reported-by: CDR <venefax@gmail.com>
Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: Michael H. Warfield <mhw@WittsEnd.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>