`windows-rs` is the newer, Microsoft-supported version of the API bindings; `winapi` hasn't been updated in some time. This allows us to remove some code, as `windows-rs` includes the `Sym*` functions that we had to previously defined ourselves in `dbghelp`.
Rather than port the `jobs` and `com` code I removed it, as it was unused.
The `check_hr` and `check_winapi` macros have been replaced by use of `.ok()?` on `BOOL` and `?` on `HRESULT` which now support standard error handling facilities.
