Update bindings and dependencies to WASI 0.2.0 (#471)

Update bindings and dependencies to WASI 0.2.0 (#471)

* make the Makefiles a bit more robust

- Escape "." character in `sed` regex
- Ensure that %.wasm target fails cleanly (i.e. without generating the target file) if `wasm-tools` fails

Signed-off-by: Joel Dice <joel.dice@fermyon.com>
* split `component new` rule out of link rule for Preview 2

We now explicitly distinquish between core module files (%.core.wasm) and
component files (%.wasm), which helps avoid the trickery in my previous commit.

In order to test this properly, I needed to update the Wasmtime URL to point to
v17.0.0 instead of dev (which we needed to do anyway), and that in turn required
updating the bindings to use the final WASI 0.2.0 release.

Signed-off-by: Joel Dice <joel.dice@fermyon.com>
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Signed-off-by: Joel Dice <joel.dice@fermyon.com>