Clarify the documentation about the restart function

Restart has never been able to be overridden in OpenRc, but there is a
way to make your service script behave differently when restart is being
executed.

X-Gentoo-Bug: 480866
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=480866
Remove gentoo's net.* scripts

It has been determined that it will be best for gentoo's net.* scripts
to be in a separate package to allow independent development.
This package will be called netifrc and maintained by Gentoo.
add note to README about the net.* scripts moving to their own package
typo fix
fix typo on runscript man page

The example code had an invalid checkpath option (--dir instead of
--directory) and a mode that does not make sense for directories (664
instead of 775).

X-Gentoo-Bug: 481034
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=481034