Fix Eclipse compiler warnings

[marcphilipp]

I've split the various fixes into separate commits to illustrate why/how I fixed certain warnings.

[marcphilipp]

This fixes all compiler warnings in Eclipse.

[kcooney]

I actually prefer that we suppress warnings at the narrowest place possible. There's a lot of code in this class, and I'd like to see if we introduce new references to deprecated code

[marcphilipp]

Generally I totally agree with you. In this case, however, adding @SuppressWarnings on the class level is the only way to get rid of all deprecation warnings in TestClass because its superclass Assert is deprecated on the class-level.

[kcooney]

Maybe we should have just deprecated the methods in Assert instead of the whole class, but I think that ship has sailed :-)

[marcphilipp]

So, okay by you?

[kcooney]

Yeah, this is fine

[marcphilipp]

@kcooney I've added another commit to that fixes the serialization warning by adding a serivalver generated serialVersionUID (see #1042 (comment)).

[kcooney]

LGTM

[marcphilipp]

Good enough to merge it?

[kcooney]

Sorry, LGTM = "looks good to me" => "feel free to submit" :-)

I was going to let you merge this because I wasn't sure if you wanted to have multiple commits or squash it (either is fine)

[marcphilipp]

Ok, thanks! 😄

I think I'll remove the ValidationError change from a170a3d and squash it with 08e6b86. For the rest, I think it's better to have separate commits in this case.