Adopting a new diagram style

[ronaldtse]

The current diagram style looks like this:

It needs to be changed to something like this:

The original "style file" for PlantUML is this:

skinparam Dpi 150
skinparam Monochrome false
hide circle
skinparam Default {
  TextAlignment center
  FontName Helvetica
}

skinparam Class {
  AttributeIconSize 0
  BackgroundColor White
  ArrowColor Black
  BorderColor Black
  FontStyle bold
  StereotypeFontSize 10
}

skinparam Rectangle {
  BackgroundColor White
  ArrowColor Black
  BorderColor Black
  FontStyle bold
  FontSize 11
  StereotypeFontSize 10
}

skinparam Object {
  BackgroundColor White
  ArrowColor Black
  BorderColor Black
  FontStyle bold
  FontSize 11
  StereotypeFontSize 10
}

skinparam Entity {
  StereotypeFontSize 10
}

[w00lf]

@ronaldtse it seems that the main display feature we wont be able to implement here - graphviz does not support box-shadowing. I have not been able to find any mentions of such styling for graphviz, even for HTML labels.

Without this feature, diagrams will never visually close to our plantuml styling. I will try to search graphviz plugins that can do that, but in that case we will have an issue of actually shipping graphviz with plugins to the end users.