retern the 'skip empty fields option.'

Essentially reverts commit 292756. Because this option has existed in Semantic
Views since it was introduced, views may have been saved and exported that
relied on this option before the "hide empty fields" option was introduced in
Views. This row style plugin option is completely redundant with that field
option. Rather than upset and annoy some users who were testers and early
adopters (including myself), I'll just promise to plan this better for the next
major version.