[HistoryAction] Revert r108341 as this breaks revision delete.

[HistoryAction] Revert r108341 as this breaks revision delete.

This construction never looked cool, but looks like this fix is not the right way, so reverting it.

This form is used for two purposes:
-- Submitting diff/oldid to (implied) action=view
-- Submitting ids-array to action=revisiondelete

That makes it complicated. Also for IE6/IE7 compatibility, there is no way to do this from the HTML itself (i.e. using <input type="submit" name="action" value="revisiondelete"> would work but leaves no option to have a custom i18n label. and <button type="submit"  name="action" value="revisiondelete">I18N LABEL</button> works but IE7 submits "I18N LABEL" as value for "action" instead of "revision delete".

Will re-fix bug 33587  in a few minutes with a "progressive-enhancement" solution from the front-end instead.