s/aria/aria2/
Bug fixes

Set default for aria_config/dir so we don’t have to check it’s
existence repeatedly
Set correct parent_folders when multiple directories exist in the
torrent structure
Get movie_year and year to be set correctly when parsing movie names
Fix unicode bug when rendering fields before passing to aria2
imdb_lookup no longer tries to capitalize non-string errors. fix #2450
Make task abort properties public, for plugins to view.
Make sure email plugin does not email on silent aborts.
Fix a unit test.
Make bittorrent utility return native strings instead of byte strings.
fix #2428
Workaround for tmdb3 bug. refs #2437
Fix tvdb online test.
Make sure some possible config paths are native strings.
refs #2452
Make sure no crash when current directory doesn't exist.
fix #2452
Move history plugin to learn phase.
Make sure PluginError.value is always a string. refs #2454