Do we need public setter for Configuration.ImageFormatManager?

[antonfirsov]

Currently it's not guarded against setting it to null:

ImageSharp/src/ImageSharp/Configuration.cs

Lines 114 to 117 in e11f318

	/// <summary>
	/// Gets or sets the <see cref="ImageFormatManager"/> that is currently in use.
	/// </summary>
	public ImageFormatManager ImageFormatsManager { get; set; } = new ImageFormatManager();

I'm wondering if we need the public setter at all? No test cases exercise it, every call site seems to modify the existing collection.

[JimBobSquarePants]

There doesn't seem to be a way to clear the collection. There's only ClearImageFormatDetectors which doesn't actually clear the ConcurrentBag and replaces it with a new instance instead.

This is an odd class....

[antonfirsov]

We should attempt to clean it up. 2.0 is a good chance to introduce breaking changes if necessary.

[JimBobSquarePants]

Yeah I think we definitely should.