Prettier schedule DOT export

[martinjonsson01]

Reason

To generate better graphs for the thesis (and for demos, presentations and supervisor), make the DOT export of the schedules contain more formatting and information.

Requirements

• Batches are grouped into boxes (assuming that all systems in a batch finish executing at the same time)
• (?) transient dependency arrows are skipped
• (?) color-coding of systems accessing same components
• Printing of schedule during execution takes into account current state:
  • Already executed systems are greyed out
  • Pending systems are highlighted
  • Dependencies to systems that will be "unlocked" are highlighted

Dependencies

• Integrate scheduler prototype into MVP #36