[css-logical] Logical caption-side issues

[Loirooriol]

CSS Logical says

The existing top and bottom values are idiosyncratically redefined as assigning to the block-start and block-end sides of the table, respectively.

What about left and right? According to CSS Tables, Gecko is the only implementation, and there they seem to refer to what would be the inline-start and inline-end sides of the table if direction was ltr. They don't refer to the physical left and right.

The mapping on this property uses the writing mode of the element’s containing block (that is, the table wrapper box).

But CSS Tables doesn't say that the writing-mode value of the table element is used in the table wrapper box, this means it's used in the table grid box instead. However, setting writing-mode on the table element affects the position of its caption on both Firefox and Chrome.

Also, the spec says "uses the writing mode". Writing Modes spec explains this depends on all writing-mode, direction, and text-orientation, but I think it's easy to misunderstand and believe that only writing-mode is included. I would explicitly mention all properties, just like in most other sections.

[fantasai]

CSS Tables does not correctly define the way properties are applied to tables. That's a general problem with that spec... in general, all inheritable properties are applied to the table wrapper box.

Added definitions for left and right in d919691