Update patmch_v1.d

[mikey-b]

Rewritten to give D a strong chance at the benchmark.
Unfortunately, there are some limitations to the D regex regarding encoding (As you found). https://dlang.org/phobos/std_regex.html#Unicode%20support

You can clean the howto file with
iconv -f iso-8859-1 -t utf-8 howto > howto2

Line 12 can be rewritten with a compile-time generated Regex engine,
auto re = ctRegex!(r"([a-zA-Z][a-zA-Z0-9]*)://([^ /]+)(/?[^ ]*)");
if you feel it fair to sacrifice the command-line pattern option.