title: Combining data frames with unequal number of columns
body: <p>Suppose I have two data frames, Dat1 and Dat2,</p>
  
  <pre><code>Dat1
  Col1 Col2 Col3
  A1    56   89
  </code></pre>
  
  <p>and</p>
  
  <pre><code>Dat2
  Col1 Col2 Col4 Col5
  A2   49    84   F11
  </code></pre>
  
  <p>Finally I want to have a combined data frame which looks like</p>
  
  <pre><code>Col1 Col2 Col3 Col4 Col5
  A1    56   89   NA    NA
  A2    49   NA   84    F11
  </code></pre>
  
  <p>Is it possible to achieve this in R?</p>