TODO for RT-Extension-ReferenceIDoitObjects

*   [Feature] Implement various tree views, e. g. physical location.
*   [Feature] Make field for email addresses configurable (currently only
    'Requestors').
*   [Feature] Add new tab to search for i-doit objects.
*   [Feature] Abtract from custom field names and put them into the lib.
*   [Bug (unconfirmed)] no JavaScript/jQuery map() support in IE < 9;
    workaround:
    <https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/map>
