Grouping settings per component/instance

[LourensVeen]

Settings can be specified specifically for a given component using the instance.setting: 123 syntax under settings:. If you could nest them hierarchically, then that would save a lot of typing if you have many such instance-specific variables. Instead of

settings:
  macro.x = 1
  macro.y = 2
  macro.z = 3

you could write

settings:
  macro:
    x = 1
    y = 2
    z = 3

Since we don't allow mapping-valued settings, this would not be ambiguous, although if we ever do allow mapping-valued settings then this will become a problem.