Some tweaks

Hi! Unfortunately we still dont have a theme that could serve as good example nor documentation of the options. Just file an issue if you have questions about the theming - Someday we could compile a tutorial out of it.. or  better first rewrite RenderTheme to use something different than xml.
btw the osmarender theme is a quick port of the original mapsforge theme that is why it contains things like circle or stroke-array are not handled by vtm.