While there, embed rc.embedded and fix permissions of rc.halt.

Suggested by: Jim Thompson <jim@netgate.com>

While there, switch to the defaults when reloading the webgui.

I know, I know, backing up rrd and restoring it after reboot seems
like overkill, but the good thing is that if you ever decide to
install from a clean image the config import is able to pick up
your backups as well and you will not lose any history.