Model and recognize sequence of events

[derwehr]

Enable BLAST to specify and check for sequences of events with blocks.
i.e.
Button A Event, then Button B Event

[derwehr]

Notes:

• Is A - C - B an instance of A - B or only if B follows directly after A?
• We could introduce named panes to the workspace - each modelling a different state, and then add blocks representing transitions from the current state to another one.