Cms: Improve the way we access next/previous entries

[jackmcdade]

We have some bugs

Right now the collection:next and collection:previous tags are reversed when in a dated context. Given the most common use case of beginning to read/browse at the beginning/newest entry (LTR) and going onwards to the older, you would have these links:

<< Previous (already read, newer) || Next (haven't read, older) >>

This is easily confusing though, and I know we've had it wrong a dozen times at various phases of dev (v1, v2, v3) and maybe I have it wrong now and am thinking backwards. Please correct me if so.

I tried to fix it locally in the template by adjusting the sorting (date:desc), but the param wasn't respected.

We could be clearer

I think we should also add collection:newer and collection:older tags/aliases to make this much easier to intuit. Way less confusing, and would only apply to dated collections.

[edalzell]

I never ever ever remember which way is "next" due to sorting, I'd love something clearer like newer that looks at the sorting, for date collections.

[jesseleite]

Fixed, and added collection:newer and collection:older.