The filter walked its list of access rules but tested the first entry each
time round, so anything pcre_extend appended was never consulted and the
command did nothing at all. Test the entry the loop is on.
pcre_extend takes an ACE and no FILTER_ACTION - the rule keeps the action it
was given - so correct the manual, which documented an argument the command
does not read.
The tests cover matching and denial, rule order, client headers, matching
options, the access rule a pcre rule carries, pcre_extend, and rewriting a
reply header and reply data. Request rewriting is covered through an HTTP
parent, which is the path where it reaches the wire.