[UI] add possibility to have `aside` as a tab-style interface

[dariok]

Currently, there are #fac and #ann in aside but they simply sit there.

As we use jQuery and jQUI anyway, we can use their mechanisms to make this a tab interface. As all of this can be done using JS, we do not need additional configuration etc. but can use the usual instance and project specifics.

Main task: add docu that states how to do this:

• if necessary, change – via JS! – text in aside ul li
• if necessary, add – via JS! – an aside ul li and an aside div with links as per the existing example
• activate the tabs via

  $('#wdbRight ul').show();
  $('#cnt').show();
  $('#wdbRight').tabs();

[dariok]

This could be used for text-internal navigation (see #321 and #329)