title: Git Submodules: how to know the commit/tag of the submodule
body: <p>due to company policies, we have very little tools in the toolbelt. I'm stuck with using Git for a number of things where <em>another tool</em> would do the work better, faster.</p>
  <p>I need a specific dll in my project and the fastest way to get it was found to add a second repository as a submodule. I'm in the testing department, so I don't need the latest dll, nor the stable branch of the dll. I need a specific version of said dll, and I need fine control over it.</p>
  <p>Luckily, I can use tags to navigate to the specific version. By <code>git checkout &lt;tag&gt;</code> I send the submodule in detached head and I can freeze the information with a commit of the superproject. Running <code>git status</code> doesn't explicitly tell me where I am with the submodule.</p>
  <p>How can I explicitly get the information regarding tag the submodule is aligned within the detached head from the superproject? Ideally, I would like to have this information stored in plain text, for instance in the <code>.gitsubmodules</code> file. I want to be positive that the submodule is aligned with a given tag (or commit if the tag is not available) and I want to have this testable automatically.</p>