array_merge_recursive() results in a misbehavior making arrays from
scalar options when current and default values differ. Replcae it by
array_replace_recursive() should resolve the issue for now.
The user agent filer list is not flipped with the actual values as keys
like the lists for referrer and target. Hence the numeric keys are
compared against the actual user agent. We now flip the values in the
upgrade hook.
The plugins purpose is to exclude or filter certain requests from
tracking by Statify. However the current name "Statify Blacklist" is not
actually inline with today's understanding of such terms. In WordPress
Core 5.5 the word "blacklist" among others has been replaced by more
precise wording where possible.
The term "filter" has been used in various places already and clearly
describes the behavior of this plugin. So we rename the plugin to
"Statify Filter" and rephrase front-end texts.
Plugin slug (permalink), textdomain and all public class and constant
names left untouched for now, to not introduce breaking changes at this
point. To be cleaned up with next major release.
