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/doc/_static/custom.css

@@ -0,0 +1,17 @@
+/* customizations to Alabaster theme . */
+
+div.document {
+    width: 1480px;
+}
+
+div.body {
+    max-width: 1280px;
+}
+
+div.globaltoc {
+    font-size: 1.4em;
+}
+
+img.logo {
+    height: 120px;
+}