New content: Concurrent programming

[LinqLover]

This is just an idea, we might implement or discard this. Contents that could be covered by the added chapter/section whatever:

• Processes (the processor its scheduling; fork, suspend, resume terminate, terminateAggressively; Process Browser)
• Synchronisation (semaphores, mutexes, deferred UI messages)
• Futures and promises
• Coroutines and generators

Currently, some of these contents are already mentioned in the book, but IMHO they are a bit scattered:

• Chapter 6 introduces the process browser and the scheduling implementation briefly from a non-programming perspective
• Infos that are missing here: prioritized time-slicing, cooperative scheduling per priority/preemptive scheduling for higher priorities (unsure about the exact terminology here)
• FAQ 20. mentions a few classes in Kernel-Processes only by their name

Questions:

• Do we want to describe the proposed concepts in greater detail?
  • Many synchronization concepts are not specific to Squeak, so we could also assume them. Still, the programming interface and the vocabulary are specific to Squeak.
  • Non-standard concepts include UI messages and maybe coroutines
• Or should we at least add a reference from chapter 6 to the FAQ and vice-versa?

[LinqLover]

For now, just add a few pointers in the existing FAQ. A "chapter 13" is not planned for now.

[LinqLover]

• Later, move the section on the process browser into the new chapter.