Add methods for round(ed) things

[moehreag]

• circles (filled / outline)

• rounded rectangles (filled / outline)

• restructure DrawUtil

[TheKodeToad]

I could review, but as i've said, I'm not a huge fan of this :|

[moehreag]

I could review, but as i've said, I'm not a huge fan of this :|

well, either

• provide an idea for a better implementation
  or
• elaborate on your statement (f.e. that "it doesn't fit the style" in your opinion or something)

It's fine to not like things, we just need to find a solution. This does not mean that the only solution is to merge this, there obviously are others as well.