Generation 2 of the iOS app:

Goal:

- Simplified plumbing and largely reduced risk of things going
  horribly wrong.

Ideas:

- No more FakeSockets.

- No more large number of threads emulating the processes and threads
  in web-based Online.

- Still based on WebView, though, and the same Online JavaScript still
  used.

- The completely unrelated "FakeWebSocket" thing in our JavaScript is
  not going away.

- Just handle incoming messages from JavaScript and callbacks from LO
  core as received. Either directly or by scheduling a block to be
  executed. Do not pretend that there is a bunch of processes that
  need to use sockets for IPC as in web-based Online. Do not pass
  messages between threads using FakeSockets.

- Reduce and simplify the use of the Online C++ code.

Steps:

- Re-factorings that don't affect any working of current Online or
  apps, but which will make the iOS app re-plumbing easier.

- ...

Problems:

Clearly this change can't be done in one step, and is not necessarily
of high priority, but has to be done over a period of several months.
How to make sure other changes done to Online at the same time don't
interfere? If kept in a branch, changes from the master branch must be
merged in on an almost daily basis.

When some of the functionality in Online C++ can/should be re-used
after all (probably things like the basic handling of messages, where
one might guess that large chunks of code is re-usable), separate out
such functionality into a class of its own in the master branch first,
and use that then in the gen2 branch.

What about the Android app? There hardy is interest to make similar
changes to it, if it works fine already, and there is no need to make
it handle multiple open documents in the same app process. Need to
keep the FakeSocket code for it, etc.