feat: bring back and adapt python bindings with rust core

* import python, try to adapt for rust

* add missing wrapper functions

* - try to write up how to build python bindings
- strike some unused functions from deltachat.h

* adjustments to make tox work

* try to run circle-ci with python build

* don't do docs

* running cargo test as well

* don't run cargo test anymore, that's done in other ci jobs

* also build docs

* don't run doxygen anymore

* subst C with Rust

* a try to get better wheels

Closes #41

ci_scripts/docker-coredeps/Dockerfile

@@ -0,0 +1,25 @@
+FROM quay.io/pypa/manylinux1_x86_64
+
+# Configure ld.so/ldconfig and pkg-config
+RUN echo /usr/local/lib64 > /etc/ld.so.conf.d/local.conf && \
+    echo /usr/local/lib >> /etc/ld.so.conf.d/local.conf
+ENV PKG_CONFIG_PATH /usr/local/lib64/pkgconfig:/usr/local/lib/pkgconfig
+
+ENV PIP_DISABLE_PIP_VERSION_CHECK 1
+
+# Install python tools (auditwheels,tox, ...)
+ADD deps/build_python.sh /builder/build_python.sh
+RUN mkdir tmp1 && cd tmp1 && bash /builder/build_python.sh && cd .. && rm -r tmp1
+
+# Install Rust nightly 
+ADD deps/build_rust.sh /builder/build_rust.sh
+RUN mkdir tmp1 && cd tmp1 && bash /builder/build_rust.sh && cd .. && rm -r tmp1
+
+# Install a recent Perl, needed to install OpenSSL
+ADD deps/build_perl.sh /builder/build_perl.sh
+RUN mkdir tmp1 && cd tmp1 && bash /builder/build_perl.sh && cd .. && rm -r tmp1
+
+# Install OpenSSL
+ADD deps/build_openssl.sh /builder/build_openssl.sh
+RUN mkdir tmp1 && cd tmp1 && bash /builder/build_openssl.sh && cd .. && rm -r tmp1
+

ci_scripts/docker-coredeps/deps/build_openssl.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -e -x
+
+OPENSSL_VERSION=1.1.1a
+OPENSSL_SHA256=fc20130f8b7cbd2fb918b2f14e2f429e109c31ddd0fb38fc5d71d9ffed3f9f41
+
+curl -O https://www.openssl.org/source/openssl-${OPENSSL_VERSION}.tar.gz
+echo "${OPENSSL_SHA256}  openssl-${OPENSSL_VERSION}.tar.gz" | sha256sum -c -
+tar xzf openssl-${OPENSSL_VERSION}.tar.gz
+cd openssl-${OPENSSL_VERSION} 
+./config shared no-ssl2 no-ssl3 -fPIC --prefix=/usr/local
+
+sed -i "s/^SHLIB_MAJOR=.*/SHLIB_MAJOR=200/" Makefile && \
+sed -i "s/^SHLIB_MINOR=.*/SHLIB_MINOR=0.0/" Makefile && \
+sed -i "s/^SHLIB_VERSION_NUMBER=.*/SHLIB_VERSION_NUMBER=200.0.0/" Makefile
+
+make depend
+make 
+make install_sw install_ssldirs
+ldconfig -v | grep ssl 

ci_scripts/docker-coredeps/deps/build_perl.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+PERL_VERSION=5.28.0
+PERL_SHA256=7e929f64d4cb0e9d1159d4a59fc89394e27fa1f7004d0836ca0d514685406ea8
+curl -O https://www.cpan.org/src/5.0/perl-${PERL_VERSION}.tar.gz
+echo "${PERL_SHA256}  perl-${PERL_VERSION}.tar.gz" | sha256sum -c -
+tar xzf perl-${PERL_VERSION}.tar.gz
+cd perl-${PERL_VERSION} 
+
+./Configure -de
+make
+make install

ci_scripts/docker-coredeps/deps/build_python.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+set -x -e
+
+# we use the python3.5 environment as the base environment 
+/opt/python/cp35-cp35m/bin/pip install tox devpi-client auditwheel 
+
+pushd /usr/bin
+
+ln -s /opt/_internal/cpython-3.5.*/bin/tox
+ln -s /opt/_internal/cpython-3.5.*/bin/devpi
+ln -s /opt/_internal/cpython-3.5.*/bin/auditwheel
+
+popd

ci_scripts/docker-coredeps/deps/build_rust.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -e -x 
+
+# Install Rust 
+curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain nightly-2019-04-19 -y
+export PATH=/root/.cargo/bin:$PATH
+rustc --version
+
+# remove some 300-400 MB that we don't need for automated builds
+rm -rf /root/.rustup/toolchains/nightly-2019-04-19-x86_64-unknown-linux-gnu/share/

ci_scripts/docker-coredeps/deps/run_all.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+#
+# Build the Delta Chat C/Rust library
+#
+set -e -x
+
+# perform clean build of core and install 
+export TOXWORKDIR=.docker-tox
+
+# build core library
+
+cargo build --release -p deltachat_ffi
+
+# configure access to a base python and 
+# to several python interpreters needed by tox below
+export PATH=$PATH:/opt/python/cp35-cp35m/bin
+export PYTHONDONTWRITEBYTECODE=1
+pushd /bin
+ln -s /opt/python/cp27-cp27m/bin/python2.7
+ln -s /opt/python/cp36-cp36m/bin/python3.6
+ln -s /opt/python/cp37-cp37m/bin/python3.7
+popd
+
+#
+# run python tests
+#
+
+if [ -n "$TESTS" ]; then 
+
+    echo ----------------
+    echo run python tests
+    echo ----------------
+
+    pushd python 
+    # first run all tests ...
+    rm -rf tests/__pycache__
+    rm -rf src/deltachat/__pycache__
+    export PYTHONDONTWRITEBYTECODE=1
+    tox --workdir "$TOXWORKDIR" -e py27,py35,py36,py37
+    popd
+fi
+
+
+if [ -n "$DOCS" ]; then 
+    echo -----------------------
+    echo generating python docs
+    echo -----------------------
+    (cd python && tox --workdir "$TOXWORKDIR" -e doc) 
+fi