Add a range of files to rename. Started an exclude field too.
Clean up arguments between GUI and renamer and improve error checking

* Remove imdb_season_rename() and local_season_rename()
directoryrenamer.py and replaced it with rename_shows_in_directory()
in to handle both cases.
* Remove the brackets functionality in filerename.py.
* Remove error checking for the file count from rename_on_disk() in
filerename.py. It's now being done in directoryrenamer.py.
* Clean up _gather_input() in gui_main.py to do better error checking.
* Pass a tuple to the renamer rather than a list.
* Remove rename() from imdbhelper.py.
* Update get_list_of_shows() to pass a list with only the episode names.

Nature: Clean Up