There are schemes, like SABER (#192) that have more than one principal
submitter. Consistency warrants that we turn it into a list for all
schemes and don't do something with allowing either a str or a list:
that would just be very annoying to parse.

Closes #194

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Making MS compiler happy

* More fixes for MS compiler

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Making MS compiler happy

* More fixes for MS compiler

* Started more cleanup work on Kyber768

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Making MS compiler happy

* Making MS compiler happy

* More fixes for MS compiler

* More fixes for MS compiler

* Started more cleanup work on Kyber768

* Kyber768 passing all tests locally

* Kyber512 passes all tests locally

* Kyber1024 now also passing all tests locally

* Now passing all tests with -Wmissing-prototypes

* Local tests (on Linux) passing again

Windows already complains about this in CI, but this will
let us catch these issues on Linux as well.

Windows already complains about this in CI, but this will
let us catch these issues on Linux as well.

* fix prototypes for sphincs and static functions in aes.c

* fix missing prototypes in all frodo variants

* fix missing prototypes in kyber

* remove const from non-pointer arguments in Frodo

* add missing prototypes to requirements in README

Does this slightly uglily, but it should work.

LIB is already an environment variable on Windows

clang-format was not flexible enough to allow lining out things on
columns with spaces.