Ruby tests and style-410

[dauwhe]

While researching support for -epub-ruby-position, I found it interesting that some reading systems fail the Ruby tests, but pass style-410. And some reading systems pass the Ruby tests, but fail style-410. Given that style-410 is just the initial value of ruby-position, this is weird. As written, I don't think style-410 gives us much information about the level of support for ruby-position. Perhaps these style tests should be moved into the test file that checks for ruby support itself...