Patches to keep you busy over christmas

[Sebastian Spaeth]

OK, this is a patch series over master that achieves 2 main things:
GUI revamp and true single thread mode. (the latter depends on the
former being applied so far). This is post-release material, I guess.


Revamp the GUI system to a) do away with the Curses plugin, simplify
calling the getglobalui throughout the code and give them nicer names:
(TTY, Basic, Quiet, Machine). I kept the patch as small as I could but
it is unfortunately still a bit bigger that I wish for:

9a0b4d6 Do away with UI plugins and simplify calling the GUI
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Some small cleanup patch:

d9127b8 No need to import InstanceLimitedThread sepcifically
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Implement "true" single threaded mode, with those 5 patches over master,
I can see where Exceptions occur, as everything really only happens in
one thread. Very useful for debugging and logging.

6f9f676 Catch KeyboardInterrupts and raise them
cb00f67 Implement single threading mode