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

python/install_py_bindings.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+set -ex
+
+#cd ..
+#cargo build -p deltachat_ffi --release
+#cd python
+
+export CFLAGS=-I`realpath ../deltachat-ffi`
+# the followine line results in "libdeltachat.so" not found
+# export LDFLAGS='-Wl,-rpath=$ORIGIN/../target/release -Wl,--enable-new-dtags'
+pip install -e .
+export LD_LIBRARY_PATH=`realpath ../target/release`
+python -c "import deltachat"