title: SystemJS relative paths
body: <p>I have a very basic <code>config.js</code> file that works as expected, so long as it's deployed under the root URL. Here is the sample <code>config.js</code> file:</p>
  
  <pre><code>System.config({
    //use typescript for compilation
    transpiler: 'typescript',
    //typescript compiler options
    typescriptOptions: {
      emitDecoratorMetadata: true
    },
    //map tells the System loader where to look for things
    map: {
        app: "./src",
    },
    //packages defines our app package
    packages: {
      app: {
        main: './app.ts',
        defaultExtension: 'ts'
      }
    }
  });
  </code></pre>
  
  <p>So long as this file is loaded from the root path <code>&lt;script src="/config.js"&gt;</code> and locations are<br>
  <a href="http://localhost/config.js" rel="nofollow">http://localhost/config.js</a> and <a href="http://localhost/src/app.ts" rel="nofollow">http://localhost/src/app.ts</a> it all works fine. </p>
  
  <p>I'm now trying to move the <code>config.js</code> file to a deeper directory and load it like: <code>&lt;script src="/a/b/c/d/e/config.js"&gt;</code>, but if I do this I then need to hard-code the path on the <code>config.js</code> file itself like:</p>
  
  <pre><code> //map tells the System loader where to look for things
    map: {
        app: "./a/b/c/d/e/src",
    },
  </code></pre>
  
  <p>Is it possible to not hard-code the entire path again in the <code>config.js</code> file ? I would have thought the leading <code>./</code> meant "relative to" but it doesn't. If I don't hard-code the full-path again it doesn't work. What is  (or is there) a syntax to indicate relative location ?</p>