* Put AES ctx on the heap

This forces people to use the ``ctx_release`` functions, because otherwise there will be leaks

* Put fips202 on the heap

* Add much more docs for fips202.h

* fixup! Put fips202 on the heap

* Put SHA2 on the heap-supporting API

* Fix clang-tidy warnings

* Fix unreachable free() in falcon

* Fix McEliece8192128f-sse GNU Makefile

It mentioned `sk` instead of `pk` as specified in the arguments.

Closes #205.

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

* fixes dynamic memory allocation test. previously a function called freeze() would trigger it

* this adds DilithiumII. Preprocessor conditionals still need to be removed

* fix ms Makefile

* fix MS compiler warnings

* clean-up

* remove preprocessor conditionals

* add dilithium3

* add dilithium4

* add duplicate consistency checks

* SHA2 state constants in common

* clean up symmetric.h

* Port SPHINCS+-SHA256 to sha256ctx struct

* Implement ctx struct for fips202

* Port Kyber{512,768,1024} to fips202 ctx struct

* Port NewHope to fips202 structs

* Port SPHINCS+-SHAKE256 to fips202 ctx structs

* Use opaque fips202 structs in MQDSS

* port dilithium to use fips202 ctx structs

* include -Wredundant-decls

* remove comment; format NTT constants

* reduce casts in power2round