Email address in "<a@b.c>" format broken

[sfstpala]

This code crashes with email-addresses in that format.

Here's a fix:

markdown/inlinepatterns.py

+ import html.entities
- if sys.version >= "3.0":
-     from html import entities as htmlentitydefs
- else:
-     import html.entities

via Python-Markdown/markdown#29 (comment)

I haven't tested (properly) if this breaks anything else though.