title: downgrade non-ascii symbols to closest 7-bit ASCII equivalent (preferrably Java)
body: <p>is there any simple/lightweight solution to change at least some of non-ASCII symbols to respective ASCII analogs? For example this string </p>
  
  <pre><code>abc-åäö.txt
  </code></pre>
  
  <p>should be changed to </p>
  
  <pre><code>abc-aao.txt
  </code></pre>
  
  <p>A bit of background: Zip-tools do not reliably support UTF-8, hence the need to downgrade. AFAICR Google "download attachments as single zip file" feature replaces any non-ascii symbols with the '_' character.</p>
  
  <p>PS: the code might as well be in some other language, if it's more or less understandable I'll port that to Java.
  PPS: my first question so far, so please don't minus me below the ground okay?</p>