docs/68606: Porter's Handbook: document how to write rc.subr scripts

[Pav Lucistnik]

Synopsis: Porter's Handbook: document how to write rc.subr scripts

State-Changed-From-To: open->closed
State-Changed-By: pav
State-Changed-When: Thu Nov 10 09:02:24 GMT 2005
State-Changed-Why: 
I wrote a (rather short) section to chapter 6, detailing USE_RC_SUBR and
USE_RCORDER knobs, giving port specific issues and referring to base system
rcng docs for the rest.

http://www.freebsd.org/cgi/query-pr.cgi?pr=68606