data table should not paginate past the end

[gordonwoodhull]

If the data table has beginSlice set and the data gets filtered so there are less records than that value, then nothing is displayed. One has to go to the last page to show stuff again.

It should either

• page up to where there is data, or
• reset entirely

Problem with the first option is that we don't really know the page size - it's technically just a slice. But it's probably fine to subtract some multiple of endSlice - beginSlice to get back in bounds.

[gordonwoodhull]

By design beginSlice and endSlice are really stupid and it's up to the client to keep them sensible.

A good place to keep this in check is the preRedraw handler for the table, and I added handling based on the nice pagination system @HamsterHuey developed, contributed by @dadokkio in #1492.

The updated example will be published in 3.0.9. I think that's sufficient.