Add a way to ignore expired TLS certificates

[jmairboeck]

Currently, when trying to open a website whose server's TLS certificate has expired, WebPositive just displays the unhelpful and confusing error message

Error loading <url>:

SSL peer certificate or SSH remote key was not OK

with no way to override it and display the website regardless.

I found a few older tickets that were fixed, which suggests that this should work. Maybe it was broken by switching to curl?

This is hrev57370 with HaikuWebkit 1.9.8-1

[nephele]

Haikuwebkit with curl bypasses the networking kit, and therefore also BSecureSocket

That said we don't have a generic way to add exceptions or manage the certificate store yet, so definetely room for improvements :)