ExtensionUrlHandling does not have a value for "do nothing"

[ewoutkramer]

ExtensionUrlHandling currently looks like this:

public enum ExtensionUrlHandling
{
    //
    // Summary:
    //     Do not resolve the extension
    DontResolve,
    //
    // Summary:
    //     Add a warning to the validation result when the extension cannot be resolved
    WarnIfMissing,
    //
    // Summary:
    //     Add an error to the validation result when the extension cannot be resolved
    ErrorIfMissing
}

When an extension is missing we only have the ability to raise an error or warning, or not validate the extension at all (which really means: validate against Extension, so it must still be there). There is no way to say: totally ignore this extension, and I think there's a clear usecase for that.

[ewoutkramer]

Guess that's an easy extra option, though we should more clearly document what the difference is with DontResolve, as I don't even understand that 100% now. But given my comment above, there's supposed to be a difference ;-)