[WIP] Fix comparison for classes implementing __eq__.

[icemac]

There are currently only two new failing tests:

• Comparing an object with a proxy of the object fails (but comparing the proxy with the object is fine!)
• Comparing a proxy with itself fails

But these tests run fine when deleting the __eq__ method on the Something class which is the class of self.x.

Fixes #50.

[mgedmin]

This is a WIP, right? I'm a bit confused by the commit message that says "Fix this and that" but only adds two failing unit tests.

[icemac]

@mgedmin When complete this PR will fix #50. I already added this to the description. Currently it is WIP hoping for suggestions resp. help to fix the test failures.

[icemac]

Hm, this PR does not replace the fix in zopefoundation/zope.keyreference#6. I have to investigate further.

[icemac]

These changes do not help for zopefoundation/zope.keyreference#6 because they happen on the wrong end: If self is security proxied it now gets unwrapped. But we need to unwrap other as that object is security proxied not self.

[icemac]

These changes do not help for zopefoundation/zope.keyreference#6 because they happen on the wrong end: If self is security proxied it now gets unwrapped. But we need to unwrap other as that object is security proxied not self.

That were my internal notes but looking into the diff of this PR tells a completely different story.