getSchemaKeyDefaultValue = function(schema,key) {
    var schemaKey = key
      .replace(/\./g, '.properties.')
      .replace(/\[.*\](\.|$)/g, '.items$1');
    var schemaDef = getObjKey(schema, schemaKey);
    if (schemaDef) return schemaDef['default'];
    return null;
  }
Retrieves the default value for the given key in the schema

Levels in the path are separated by a dot. Array items are marked
with []. For instance:
 foo.bar[].baz

@function
@param {Object} schema The schema to parse
@param {String} key The path to the key whose default value we're
 looking for. each level is separated by a dot, and array items are
 flagged with [x].
@return {Object} The default value, null if not found.