title: Exclude/overwrite npm-provided typings
body: <p>I've got an npm package with badly written, out of date typings. I've written my own typings and now I'm wondering if I can somehow exclude the original typings from the npm package. It's not a simple extension of interfaces, the originals are basically garbage at this point.</p>
  
  <p>Using the exclude list in tsconfig.json does not work for this purpose of course, since it still loads files from node_modules even if you exclude that folder.</p>