title: Aliasing jar target of maven_jar rule
body: <p>I have the following maven_jar in my workspace:</p>
  
  <pre><code>maven_jar(
      name = "com_google_code_findbugs_jsr305",
      artifact = "com.google.code.findbugs:jsr305:3.0.1",
      sha1 = "f7be08ec23c21485b9b5a1cf1654c2ec8c58168d",
  )
  </code></pre>
  
  <p>In my project I reference it through <code>@com_google_code_findbugs_jsr305//jar</code>. However, I now want to depend on a third party library that references <code>@com_google_code_findbugs_jsr305</code> without the jar target.</p>
  
  <p>I tried looking into both <code>bind</code> and <code>alias</code>, however <code>alias</code> cannot be applied inside the WORKSPACE and <code>bind</code> doesn't seem to allow you to define targets as external repositories.</p>
  
  <p>I could rename the version I use so it doesn't conflict, but that feels like the wrong solution.</p>