Saves the xml data to the inputed filename.
        
        :param      filename | <str>

def save(self, filename):
        """
        Saves the xml data to the inputed filename.
        
        :param      filename | <str>
        """
        projex.text.xmlindent(self.xmlElement())
        
        try:
            f = open(filename, 'w')
        except IOError:
            logger.exception('Could not save file: %s' % filename)
            return False
            
        f.write(self.toString())
        f.close()
        return True