Clean up request tracing regarding HTML quoting. Tracing may be sent to the
log, to a web page or both so the tracing module cannot expect to pass HTML
data. This change is incompatible in the sense that old calls may render
with double quoting but that's arguably better than leaking unquoted tags
to the Resolve Path web page.
The Resolve Path wizard now identifies messages containing linefeeds and
present them in <pre> style to maintain columns etc.