To avoid conflict with plan9 rc shell we need to rename our rc.
Original name come from debian invoke-rc.d, shortened into rc.

Signed-off-by: Sebastien Luttringer <seblu@seblu.net>
Signed-off-by: Tom Gundersen <teg@jklm.no>

cc199761

 assumes that /etc/rc.d scripts will exit with a value of 0 or
1. Since this can't be guaranteed, clamp the return value to 0 or 1
before adding it to the exit value.

Note that a lot of /etc/rc.d scripts don't properly exit with 0 or 1, so
this is more of a forward looking change in the hope that these scripts
are cleaned up.

Signed-off-by: Tom Gundersen <teg@jklm.no>

rc helper now call rc.d scripts in root directory with a clean environment.
Chosen vars came from init man page.

It allows to launch scripts from the command line, as if they had been launched by init

Signed-off-by: Sebastien Luttringer <seblu@seblu.net>

This is allow a quick calling to /etc/rc.d scripts by calling a shell command.
By example, starting sshd and gpm can be done by typing: rc start sshd gpm
rc can also list available scripts and show which is started/stopped in DAEMONS

[tomegun: fixed detection of autostart of background services]

Signed-off-by: Sebastien Luttringer <seblu@seblu.net>
Signed-off-by: Tom Gundersen <teg@jklm.no>