Initial reorg.

This is largely the same as #305, but updated for the current tree.

crates/misc/py/README.md

@@ -0,0 +1,20 @@
+Python 3 extension for interface with Wasmtime/Cranelift.
+
+# Build
+
+First, you'll need to install some Python dependencies:
+
+```
+$ pip3 install setuptools wheel==0.31.1 setuptools-rust
+```
+
+Next you can build the extension with:
+
+```
+rustup run nightly python3 setup.py build
+```
+
+Note that a nightly version of Rust is required due to our usage of PyO3.
+
+This will create a directory called `build/lib` which you can add to
+`PYTHONPATH` in order to get `import wasmtime` working.