Update MD013/line-length to allow long lines composed only of emphasized/strong links (fixes #67).

test/long_lines.md

@@ -8,6 +8,10 @@ This line however, while very long, doesn't have whitespace after the 80th colum
 
     [This long line is comprised entirely of a link](http://example.com "But is inside a code block") {MD013}
 
+```md
+[This long line is comprised entirely of a link](http://example.com "But is inside a code block") {MD013}
+```
+
 This [long line is comprised mostly of a link](http://example.com "This is the long link's title") {MD013}
 
 [This long line is comprised mostly of a link](http://example.com "This is the long link's title") text {MD013}
@@ -21,3 +25,21 @@ This long line includes a simple [reference][label] link and is long enough to v
 [Link to broken label][notlabel]
 
 [notlabel\]: notlink "Invalid syntax for a link label because the right bracket is backslash-escaped {MD013}"
+
+[](http://example.com "This long line is comprised entirely of a link with empty text and a non-empty title")
+
+*[This long line is comprised of an emphasized link](http://example.com "This is the long link's title")*
+
+_[This long line is comprised of an emphasized link](http://example.com "This is the long link's title")_
+
+**[This long line is comprised of a bolded link](http://example.com "This is the long link's title")**
+
+__[This long line is comprised of a bolded link](http://example.com "This is the long link's title")__
+
+_**[This long line is comprised of an emphasized and bolded link](http://example.com "This is the long link's title")**_
+
+**_[This long line is comprised of an emphasized and bolded link](http://example.com "This is the long link's title")_**
+
+*[](http://example.com "This long line is comprised of an emphasized link with empty text and a non-empty title")*
+
+**[](http://example.com "This long line is comprised of a bolded link with empty text and a non-empty title")**