Fourth major update

New methods, mostly for mpyc.runtime.Runtime alias mpc:

• mpc.sorted(), mpyc.seclist.sort(), using __lt__() as fundamental comparison operator, just as in Python.
• mpc.argmin/argmax() methods.
• mpc.all/any(), for any iterable like mpc.min/max/sum/prod() now do as well.
• mpc.transfer() for public communication of pickable objects, including objects with (dynamic) MPyC types.

Demos:

• New unanimous.py for unanimous voting (generalized matchmaking) between t+1 voters and t extra parties for maximal privacy.
• Revamped lpsolver(fxp).py demos now have .csv datasets nicely rendered on GitHub, with objective function as "header" row.
• Prettify MNIST digit printing on console.
• Use mpc.transfer() in demos helloworld.py, parallelsort.py, bnnmnist.py, cnnmnist.py, and ridgeregresssion.py.

Technical changes:

• Automatic type conversion for b = mpc.output(a), e.g., a of type SecFxp to b of type float (set flag raw to override).
• New SecureObject hierarchy in mpyc.sectypes (NB: base class SecureObject instead of Share with slot share instead of df).
• Hopping program counter of constant size (8 bytes on 64-bit Python, 4 bytes on 32-bit Python).
• Use of gmpy2 is now optional via the --no-gmpy2 command line option.
• Enhancements to mpc.to_bits() and mpc.convert().
• Add exception handling for MPyC coroutines, e.g., suppressing spurious 'Task was destroyed but it is pending!' messages.
• Plus lots of other things.

Many thanks to @b-kamphorst, @niekbouman, @skorzili, @ThomasTNO, and @toonsegers for their recent contributions.

Corresponds to package mpyc 0.7 on PyPI.