Error column in VOResource

[Roy Williams]

> If you attach all the metadata to every field element, it expands from
> just a few characters "<td> </td>" to a hundred or more.

Its not just that, there is also a structural problem.

VOTable as it stands is a *generic* container. A single tool can handle any
table (think of VOPlot or Excel). But if every element is part of a specific
markup, then we must have a different software implementation for each
different table header.