add a line between two options for better UI

there is no line between the option to show/hide featured articles and the amount of articles to show in this module.
Without the line people (read: me) can read it as: How many featured articles can be shown. Therefor I was looking for the field to set the amount of other articles I can show. 

With the line between the option show/hide featured articles and the field amount people (read: me) have better understanding of the meaning of amount.
commit change: swapping fields instead of a separator line.
removing obsolete separator line

as mentioned by @Smanzi in Pull Request https://github.com/joomla/joomla-cms/pull/5199 there are two separator lines right after each other. (https://cloud.githubusercontent.com/assets/4165717/5205697/c6c40ebc-7599-11e4-99ec-6150c632c358.PNG)
One of them is obsolete. This pull request removes the second separator line.
Merge pull request #5199 from hans2103/patch-4

swap two options for better UI