Fix RSA example scripts to cope with change to "by"

Remove unnecessary structure bracketting

As per 89fc99bc3, but on as many examples as a grep -R can find.

Move examples/miller/RSA up to examples/ (replacing older RSA there)

This removes some unnecessary redundancy in examples: the two copies
of RSA are mostly identical.

Removed trailing whitespace from all .sml and .sig files.

This affects over 900 files and was done using emacs's delete-trailing-whitespace
function in batch mode. Building the system with Poly/ML and Moscow ML seems to
work, so I'm hoping these changes don't break anything. Please complain if
they do!

Builds on Kan.0.

Oops, should have done this before!