title: Fill a vector with weekdays only
body: <p>I know the start date <code>start</code> and the last date <code>maturity</code>. How can I fill in a vector with dates without taking weekends dates into account ? 
  For instance, let's say :</p>
  
  <pre><code>&gt; start = as.Date("2013-02-28");
  &gt; maturity = as.Date("2013-03-07");
  </code></pre>
  
  <p>I would like to get the following vector as a result : </p>
  
  <pre><code>results
  [1] "2013-03-01" "2013-03-04" "2013-03-05" "2013-03-06" "2013-03-07"
  
  
  
  &gt; start = as.Date("2013-02-28");
  &gt; maturity = as.Date("2013-03-07");
  &gt; x &lt;- seq(start,maturity,by = 1)
  &gt; x
  [1] "2013-02-28" "2013-03-01" "2013-03-02" "2013-03-03" "2013-03-04" "2013-03-05"
  [7] "2013-03-06" "2013-03-07"
  &gt; x &lt;- x[!weekdays(x) %in% c('Saturday','Sunday')]
  &gt; x
  [1] "2013-02-28" "2013-03-01" "2013-03-02" "2013-03-03" "2013-03-04" "2013-03-05"
  [7] "2013-03-06" "2013-03-07"
  </code></pre>
  
  <p>Same results... ?</p>