title: Cannot pass array to angular directive
body: <p>Cannot pass an array to input mask plugin in Angular. 
  Maybe somebody can help me with this.</p>
  
  <pre><code>angular.module('myproject.directives').   
  directive('inputMask', function() {
      return {
          restrict: 'A',
          scope: {
              inputMask: '@'
          },
          link: function(scope, el, attrs) {
              $(el).inputmask(attrs.inputMask);
          }
      };
  });
  
  &lt;input type="text" input-mask="{'mask': '9{4} 9{4} 9{4} 9{4}[9]', 'autoUnmask': 'true'}" /&gt;
  </code></pre>