ENH: Add <ipmatches> and <ipjailmatches> tags

Example use filter also added for sendmail-whois with ipmatches rather
than grepped lines

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As per discussion in #480

Something to note here is I had to remove the `\n` from being escaped, such the lines do not run together. I don't believe this should cause any issues as long as we are careful to quote and in placement of any use of the _*matches_ fields.