Reduced some logging levels in (legacy) ConvertTcx to FINEST.
Add logic to detect 'illegal' Nike+ passwords (their webservice can't handle XML's 5 "predefined entities").

More info on the predefined entities here:
  http://en.wikipedia.org/wiki/List_of_XML_and_HTML_character_entity_references#Predefined_entities_in_XML

Nike+ admit this themselves, but give a completely incorrect list of illegal characters (I've tested them):
  http://support-en-us.nikeplus.com/app/answers/detail/a_id/31352/p/3169,3195