Move field collection name out of <th> and into <table><caption>

Currently the field name of the field collection is rendered as the th of the first column (the column with the row weights). I feel that the field collection name should instead be rendered in a table caption: http://www.w3schools.com/tags/tag_caption.asp

This would provide a better user experience, easier theming, better accessibility, and better adherence to web standards.

After all, the table column that has the weights contains weights and should not have the column header title of the filed collection name.

I will try to get a patch together if anyone else thinks this is a worthwhile idea.