title: R - merge lists with overwrite and recursion
body: <p>Suppose I have two lists with names,</p>
  
  <pre><code>a = list( a=1, b=2, c=list( d=1, e=2 ), d=list( a=1, b=2 ) )
  b = list( a=2, c=list( e=1, f=2 ), d=3, e=2 )
  </code></pre>
  
  <p>I'd like to recursively merge those lists, overwriting entries if the second argument contains conflicting values. I.e. the expected output would be</p>
  
  <pre><code>$a
  [1] 2
  
  $b
  [1] 2
  
  $c
  $c$d
  [1] 1
  
  $c$e
  [1] 1
  
  $c$f
  [1] 2
  
  $d
  [1] 3
  
  $e
  [1] 2
  </code></pre>
  
  <p>Any hint?</p>