New test function for marker types and sizes for regular line plots.

New test that shows the flaws in the present size translation for marker sizes in regular line plots. (NB; I replaced my files with the most up to date code earlier today, so the test is performed with the code as it is in @nschloe 's master brancho per now.)

![acid_page_1](https://f.cloud.github.com/assets/380049/2346464/30136576-a542-11e3-9018-7f5ec88a057d.png)