#104 url in email not correctly encoded

[Alberto Franco de Sa Ribeiro]

This problem n 0.4.2
When sending an email to register an external user, the link is translated to an invalid link in some webmails like hotmail. The path "?action=register&regid=" is translated to "?action=register®id=". This problem is described in http://stackoverflow.com/questions/15532252/why-is-reg-being-rendered-as-%C2%AE-without-the-bounding-semicolon

The patch attached may correct tis problem.