I'm transitioning to using exclusively instance-level fields instead of
class-level fields in plugin objects, but I neglected to bring inline and
rewrite into the future. This manifested as silent inaction on the part of
these plugins.
This change restores the old behavior (for compatibility) but also updates the
plugins to use the new behavior.
This commit makes rewrite explicitely match items using the .lower() function
instead of using Pythons builtin re.I flag.
This is required as the re.I flag only allows for case-independent pattern
matching with ascii chars. Even worse, the pattern is stored in lowercase when
using re.I, but the value to be matched isn't lowercased.
Example:
[rewrite]
artist Сергей Васильевич Рахманинов: Sergei Rachmaninoff
