MFC r261931,r261932:

  Allow overriding rctl.conf(5) file location for /etc/rc.d/rctl

Approved by:	bapt (mentor, implicit)
MFC r261934:

  Rework rctl(8) manpage

Approved by:	bapt (mentor, implicit)
MFC: r261549

Add a manpage for the urndis driver.

Obtained from:	OpenBSD