Internationalized domain names are not encoded

[ljosa]

In order to match Django behavior, internationalized domain names should be IDNA encoded. For instance, if a user enters “www.røasenter.no”, the link should go to “www.xn--rasenter-54a.no”. In other words,

urlize('www.røasenter.no')

should return

"<a href="http://www.xn--rasenter-54a.no">www.røasenter.no</a>"

Instead, it returns

"<a href=\"http://www.r%C3%B8asenter.no\">www.røasenter.no</a>",

which also seems to work, but is different from what Django returns.

See the test named IDN in test_urlize.js.