1.0.9: Added (undocumented) support for 'file' input type

- Added a new expectedInput type, 'file'

- Enables devs to specify that (API and UI) clients should supply a file
  input for the job. The UI renders this as an <input type="file" />

- Using a file input in a template expression (e.g. '${inputs.someFile}')
  automatically coerces the user-supplied file into a local filepath that
  your application can read.

  - This is effectively sugar for '${toFile(inputs.foo)}', but with some
    extra quality-of-life benefits.

  - The main QOL benefit is that Jobson will try to leave the user-supplied
    filename untouched, which is useful if your application relies on
    extension matching

- This feature is currently undocumented due to time constraints. The final
  API of the released version *should* (famous last words) be identical.