Bug fixes and changes to make using this project easier

[stevenao]

• Incorporate @jbparker changes with some tweak
• Fixed up the missing resx and pfx files
• Fixed owin selfhost request body not seekable exception
• Put a proper message for multiple descriptor in metadata document not implemented exception
• Added Metadata.ValidForDays setting to make new users experience better, as hard coding to 7 days from now will create a lot of confusion for users.

[TheDarkTrumpet]

This is a lot of changes, but it appears to address issues I'm having with VS 2017 and missing files. Is there any chance of getting this merged into master?

[elerch]

There's a ton of changes and also some merge conflicts. I'm also torn regarding the missing files - I think it's useful to not provide an out of the box F5 experience on this project as it would be tempting to just deploy the code to prod without replacing the dev certs. I'm looking at a revamp of the project to clean it up, move to .NET Core 2, etc but it's been hard to me to find the time to dedicate to the project. In the meantime I want to keep this PR open as it highlights the F5 issue that I do want to address.

[TheDarkTrumpet]

Thanks for the quick reply. I understand not merging it due to the risk of people deploying. From where I'm coming from....I know very little about saml/oath/openid/etc in general, so one big goal for me is to develop a test app with this stuff working with shibboleth (https://www.testshib.org/) just to understand how this stuff ties together. Been been painful really finding a good holistic example in .NET 4.X (or any .NET).

On an unrelated note, just so you're aware - the SAML2.AspNet is not on nuget at all. The Core one is, but not the AspNet. I'm testing now with the library you forked from, seeing if I can get something working then publish the code here on github. Hoping to help with documentation. If I get that far, I'll try and share back what I have with you. It may help with documentation.