posix-sh does not support pipefail this way

Script to enable setup mode and reboot

Fixes #2412

The package rebuild logic of OpenWrt only checks regular files. Avoid
symlinks in the files directory to make rebuilds more robust.

OpenWRT 19.07 enables urngd by default, so haveged is redundant.

many AVM devices do not have RESET/WPS buttons. So use the otherwise unused DECT/PHONE button to boot the device into setup mode.

This patch allows to enter the setup-mode by pressing the phone button
(often labeled as DECT) in addition to WPS and reset button.

This patch is necessary to allow supporting boards without a WPS and reset
button (e.g. AVM FRITZ!Box 7312).

With this commit, the status-led is set to be the "led-running"
device-tree alias for targets which do not implement the get_status_led
method in /etc/diag.sh.

Upstream commit 5eb7864a changed the method name for host-key
generation.

Some files have received some additional refactoring.

rpcd is not included in our images anymore since switching to gluon-web, so
we don't need to disable it anymore.

Fixes #121

Based-on-patch-by: Tobias Hachmer <tobias@hachmer.de>

Fixes #764

Also backport some patches improving QCA956x support.

Avoid commiting configs inbetween to decrease number of flash writes.

Fixes #714.

This allows to reach the node in setup mode over the same link-local IPv6
address as br-client uses during normal operation.

OpenWrt doesn't set the regdom unless a WLAN device is started. Explicitly set
the regdom in the setup mode to get the correct list of allowed txpower entries
in the planned LuCI module.

Moving the scripts to a common directory not only vastly simplifies the
zzz-gluon-upgrade script, but also allows to define an ordering of such
scripts across packages.

By setting setup_mode.skip to true in site.conf the device will skip
setup mode on first boot.

When an early reboot is triggered because an upgrade script has disabled the
config mode, we need to explicitly call /etc/init.d/done, otherwise the overlay
will not be finalized after a firstboot and we get an endless reboot loop.

Since switching to Barrier Breaker/procd, we'd not notice if we were
upgrading from a version before renaming the config file to gluon-setup-mode
as the upgrade scripts run after the preinit.

Fix this by checking later during setup mode init again and rebooting into the
regular run mode if we detect this case.

To start after haveged after the recent update.

gluon-config-mode retains the luci frontend, all setup scripts and config is
moved to the new package.