Major Changes

Various performance improvements
- Added dunder slots (__slots__) iterable to most classes created a lot during runtime to improve performance
  - In testing, looks like this improved speed of non image creation by ~25% (scales with number of shows)
- Changed alphanumeric string filtering from regex to str.isalnum method
  - About 7 times faster for medium length titles (scales with title length)
- Moved Show translation progress bar updating to post translation existence check
- Moved some mkdir calls to post file existence check
Allow for transparent genre cards
- Add --borderless option to fixer to omit border, create transparent cards
- Closed #100

Major Fixes

N/A

Modified fixer season image downloading to not take manual API key (uses preference file)

Fix for archives with illegal filenames
Don't reread font file if font doesn't have character
Fix for font validation on TTC fonts with more multiple embedded fonts
- See fonttools/fonttools#1664