title: Capitalizing letters. R equivalent of excel "PROPER" function
body: <p>Colleagues, </p>
  
  <p>I'm looking at a data frame resembling the extract below:</p>
  
  <pre><code>Month   Provider Items
  January CofCom   25
  july    CofCom   331
  march   vobix    12
  May     vobix    0
  </code></pre>
  
  <p>I would like to capitalise first letter of each word and lower the remaining letters for each word. This would result in the data frame resembling the one below:</p>
  
  <pre><code>Month   Provider Items
  January Cofcom   25
  July    Cofcom   331
  March   Vobix    12
  May     Vobix    0
  </code></pre>
  
  <p>In a word, I'm looking for R's equivalent of the <em><a href="http://spreadsheets.about.com/od/excelfunctions/qt/8124_proper.htm" rel="noreferrer">ROPER</a></em> function available in the MS Excel.</p>