Major cleanup.

Major cleanup.
1. Fix the order of functions to match the order they occur in
application code, making the text significantly easier to follow.
2. Do not use the same argument placeholder *sk for several different
things; call the arguments *trusted, *untrusted, and *crls as
appropriate.
3. Avoid using the word "initialised" for two different concepts
in the same manual page; it was sometimes intended to mean "fill
with zeros" and sometimes "replace the zeros with useful data".
4. Generally, make the text more precise, more straightforward,
and shorter (-84 +65 lines of mdoc code).