title: Convert cell array of cell arrays to matrix of matrices
body: <p>I can convert a cell array of matrices to matrix:</p>
  
  <pre><code>&gt;&gt; C={[1,1]; [2,2]; [3,3]};
  &gt;&gt; cell2mat(C)
  ans =
       1     1
       2     2
       3     3
  </code></pre>
  
  <p>This is OK. But, I want to convert a cell array including other cell arrays to a matrix:</p>
  
  <pre><code>&gt;&gt; C={{1,1}; {2,2}; {3,3}};    
  &gt;&gt; cell2mat(C)
  Error using cell2mat (line 53)
  Cannot support cell arrays containing cell arrays or objects.
  </code></pre>
  
  <p>So, desired output is:</p>
  
  <pre><code>&gt;&gt; mycell2mat({{1,1}; {2,2}; {3,3}})
  ans =
       1     1
       2     2
       3     3
  </code></pre>
  
  <p>How to do this?</p>
  
  <h2>Edit:</h2>
  
  <p>I want to do same thing for multidimensional ones also:</p>
  
  <pre><code>&gt;&gt; mycell2mat({{1,1;1,1}; {2,2;2,2}; {3,3;3,3}})
  ans(:,:,1) =
  
       1     1
       1     1
  
  ans(:,:,2) =
  
       2     2
       2     2
  
  ans(:,:,3) =
  
       3     3
       3     3
  </code></pre>