specials characters in the ShowTitle

filename = re.sub('[^\w\-_\. ]', '_', filename)

ensures that the filename doesn't have any special characters, but later on final_path is joined with ShowTitle which could contains special characters. Using a temporary variable because I don't want to affect metadata as well or any other part. 

Adding the recommended changes ensures that there are no special characters in the path, unless "season" has any - which I don't think it will happen.

special characters like ':' cause issues on openelec(ububtu based OK) if the strm files are generated on a network device and are shared between multiple XBMC instances. samba dosen't really like ':' in the path.