New tests from GnuTLS lessons' learned

Create new issue from https://github.com/ouspg/trytls/issues/140#issuecomment-238210168:

[CVE-2009-2730](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-2730), [CVE-2006-4790](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-4790) and [CVE-2008-4989](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-4989) from [GnuTLS](http://www.gnutls.org/security.html)
