message: Show hints in custom extractors window
  As a stop-gap measure, show text entry hints here to give some idea how
  to fill in the configuration.
diff: <border>5d</border>
  </object>
  <object class="sizeritem">
  - <object class="wxTextCtrl" name="extractor_command"/>
  + <object class="wxTextCtrl" name="extractor_command">
  + <hint translate="0">xgettext -L PHP --add-comments=TRANSLATORS: --force-po -o %o %C %K %F</hint>
  + </object>
  <flag>wxEXPAND|wxLEFT|wxRIGHT|wxBOTTOM</flag>
  <border>5d</border>
  </object>
  <flag>wxLEFT|wxRIGHT|wxTOP</flag>
  </object>
  <object class="sizeritem">
  - <object class="wxTextCtrl" name="extractor_keywords"/>
  + <object class="wxTextCtrl" name="extractor_keywords">
  + <hint translate="0">-k%k</hint>
  + </object>
  <flag>wxEXPAND|wxLEFT|wxRIGHT|wxBOTTOM</flag>
  <border>5d</border>
  </object>
  <flag>wxLEFT|wxRIGHT|wxTOP</flag>
  </object>
  <object class="sizeritem">
  - <object class="wxTextCtrl" name="extractor_files"/>
  + <object class="wxTextCtrl" name="extractor_files">
  + <hint translate="0">%f</hint>
  + </object>
  <flag>wxEXPAND|wxLEFT|wxRIGHT|wxBOTTOM</flag>
  <border>5d</border>
  </object>
  <flag>wxLEFT|wxRIGHT|wxTOP</flag>
  </object>
  <object class="sizeritem">
  - <object class="wxTextCtrl" name="extractor_charset"/>
  + <object class="wxTextCtrl" name="extractor_charset">
  + <hint translate="0">--from-code=%c</hint>
  + </object>
  <flag>wxEXPAND|wxLEFT|wxRIGHT|wxBOTTOM</flag>
  <border>5d</border>
  </object>
  