Please add option to bypass certificate validation errors

[DanStevens]

I am working with a WSDL that has a self-signed certificate. If I attempt to add the WSDL for this service, I get the following error:

error adding wsdl - The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.

I tried working around the issue by download the WSDL, but this did not work because the WSDL contains external references to XSDs.