title: Convert accented characters into ascii character
body: <p>What is the optimal way to to remove German (or French) accents from a vector of 16 million string variables.</p>
  
  <p>e.g., 'Sjögren's syndrome' into 'Sjogren's syndrome'</p>
  
  <p>Converstion of single character into a single character is better then transliteration such as</p>
  
  <p>ä => ae    ö => oe  ü => ue.</p>
  
  <p>e.g., using regular expression would be one option but is there something better (R package for this)?</p>
  
  <p><code>gsub('ü','u',gsub('ö','o',"Sjögren's syndrome ( über) "))</code></p>
  
  <p>There are SO solutions for non-R platforms but not a good one for R.</p>