* Remove the old wast and wasm2obj commands.
These are subsumed by the `wasmtime wast` and `wasmtime wasm2obj` commands.
Fixes#827.
* Remove wasm2obj install commands.
A small amount of cleanup for the top-level of this repository, where
the `installer` directory just had one misc file for the Windows
installer which we can put elsewhere inside of `ci`, another misc folder
but one that already has a few files in it.