More autolinks fixed (For #82)

[ralsina]

This PR makes most of the tests in spec/fixtures/gfm-extensions.txt:542 pass (see below) and also enables a few more cases which pass if the autolinks extension is enabled.

There are 2 cases that are failing:

First, which I can probably fix but I am just tired:

mmmmailto:scyther@pokemon.com

Should be: "<p>mmmmailto:<a href=\"mailto:scyther@pokemon.com\">scyther@pokemon.com</a></p>\n"

Is: "<p>mmm<a href=\"mailto:scyther@pokemon.com\">mailto:scyther@pokemon.com</a></p>\n"

Second, which is just wrong because that is not a valid domain (domains MUST contain a dot according to the same spec):

**Autolink and http://inlines**

Should be: "<p><strong>Autolink and <a href=\"http://inlines\">http://inlines</a></strong></p>\n"

Is: "<p><strong>Autolink and http://inlines</strong></p>\n"

If it's edited to have a proper domain like inlines.com it works properly.

[ralsina]

Sigh, that mmmmailto:foo@bar.com test case is so arbitrary 🤣

The spec for the autolinks extension says:

"All such recognized autolinks can only come at the beginning of
a line, after whitespace, or any of the delimiting characters *, _, ~,
and (."

But to match the testcase it has to be detecting foo@bar.com after a :

I can only fix it by doing a lot of special-casing for a stupid corner case which is (I think) just wrong.

[nobodywasishere]

I'd be fine with pulling that out into its own testcase and marking it as pending so the testcase with the rest of them working passes

[nobodywasishere]

mmmmailto:scyther@pokemon.com

mailto:scyther@pokemon.com

aaamailto:scyther@pokemon.com

mmmmailto: scyther@pokemon.com

mailto: scyther@pokemon.com

aaamailto: scyther@pokemon.com

[ralsina]

mmmmailto:scyther@pokemon.com

mailto:scyther@pokemon.com

aaamailto:scyther@pokemon.com

mmmmailto: scyther@pokemon.com

mailto: scyther@pokemon.com

aaamailto: scyther@pokemon.com

Makes sense, coming up

[ralsina]

Done.