More SAMLtest.id Updates

[Nate Klingenstein]

All,

The following enhancements have been added to https://samltest.id/.

* Metadata is now saved and loaded through the LocalMetadata provider, which should mean outages will be very rare, as testers can only detonate themselves.  Uploads will be much faster.
* Expired metadata is now rejected on initial upload.
* The attributes sent by SAMLtest are now listed on the metadata download page.
* Support for the Artifact binding has been added to the IdP upon user request.

Now that a gigantic metadata file no longer needs to be compiled on upload, I'll be downsizing the VM some time this evening, so there will be a little downtime.

This all entailed a lot of changes in both the providers and the upload process, so please don't hesitate to inform me if anything is broken.

Finally, I'd like to thank you for helping SAMLtest pass the 3000 entity milestone.  I hope these enhancements make it even more useful to you.

Best always,
Nate.