core (memory/crypto): replaced `PyCrypto` by `cryptography`: `PyCrypto` is unmaintained for years but was used in SàT for password hashing. This patch fixes that by replacing `PyCrypto` by the reference `cryptography` module which is well maintained. The behaviour stays the same (except that previously async `hash`, `encrypt` and `decrypt` methods are now synchronous, as they are quick and using a deferToThread may actually be more resource intensive than using blocking methods). It is planed to improve `memory.crypto` by using more up-to-date cryptography/hashing algorithms in the future. PyCrypto is no more a dependency of SàT

# Minimal makefile for Sphinx documentation
#

# You can set these variables from the command line.
SPHINXOPTS    =
SPHINXBUILD   = sphinx-build
SOURCEDIR     = .
BUILDDIR      = .build

# Put it first so that "make" without argument is like "make help".
help:
	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

.PHONY: help Makefile

# Catch-all target: route all unknown targets to Sphinx using the new
# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
%: Makefile
	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)