Possible wrong properties are returned by reflection in ReflectionExtensions.cs

[mikkelbu]

When debugging #2448 I noticed that the filtering of properties in ApplyBindingFlags has the same problem as filtering of methods in #2448. The documentation says
https://msdn.microsoft.com/en-us/library/kyaxdd3x(v=vs.110).aspx#Remarks

Specify BindingFlags.NonPublic to include non-public properties (that is, private, internal, and protected properties) in the search. Only protected and internal properties on base classes are returned; private properties on base classes are not returned.

But the code only returns private properties for BindingFlags.NonPublic

nunit/src/NUnitFramework/framework/Compatibility/ReflectionExtensions.cs

Lines 346 to 349 in 6980e95

	if (pub && !priv)
	infos = infos.Where(p => (p.GetMethod != null && p.GetMethod.IsPublic) || (p.SetMethod != null && p.SetMethod.IsPublic));
	if (priv && !pub)
	infos = infos.Where(p => (p.GetMethod == null || p.GetMethod.IsPrivate) && (p.SetMethod == null || p.SetMethod.IsPrivate));

The solution to this can probably be done similar to #2448 (replacing p.GetMethod.IsPrivate with !p.GetMethod.IsPublic), so the main issue is to write some tests that capture the intended behaviour.