Tralay - Extract and translate strings in Layout xml files.

Translatable strings in layout xml files are attributes that have name
which starts with an underscore, eg

    _title="Set Zoom"
    _label="Whole Page"

Here is how it works

 * Extract: generate out.sdf
      ../unxlngx6.pro/bin/tralay -l en-US zoom.xml > out.sdf

 * Translate: do:
      cat out.sdf > trans.sdf
      sed 's/en-US\t/de\tde:/' out.sdf >> trans.sdf 

 * Merge: translate
     ../unxlngx6.pro/bin/tralay -m trans.sdf -l de zoom.xml > zoom-DE.xml

Running

   dmake test

does something similar.