Ruby 1.9 support: following the change of Module#instance_methods
Ruby 1.9 support: following the change of Module#instance_methods

 * In Ruby 1.9, Module#instance_methods returns Array containing
   Symbol objects instead of String. To support both 1.8 and 1.9,
   "to_s" is added to every affected test method.

csw/bioruby-phyloxml