A variety of mdoc(7) and grammar changes:

A variety of mdoc(7) and grammar changes:

	* use .Bl and .El directives when using a list
	* use .Dv directive when appropriate
	* use 'The' to start a sentence instead of the function name
	* paragraph cleanups for return values
	* use approrpriate directives to markup pointers and types
	* use .Er directive for marking up errno(3) values
	* eliminate hard sentence breaks
	* use .Dv instead of .Va when documenting known constants
	* eliminate empty lines
	* spelling and grammar corrections
	* eliminate incorrect use of the .Lb directive

While I am here, add a reference to the rfork(2) manual page
under the SEE ALSO section.