Added stylesheet integration with progress delegate

- Added a style class which is used for the progress delegate
- Added a class file for custom gui
- Removed ability to change progress delegate colors using settings
Added more styling options

- Added a recognition title fix
- Progress bar and outline radius are now seperate
Added style manager

Manages stylesheets for all dialogs
More code refactoring and bug fixes

- Moved code from anime entity header to the source file
- Adding an episode to an anime that is on hold will set it to currently
watching
- If an anime which has been completed by the user increases it's anime
episode count, then it will be moved to currently watching based on the
condition that either
1) the old anime episode count is not unknown
2) the new anime episode count is not unknown
Added ability to select themes

- User can apply themes, refresh themes and refresh theme list (all of
this can be found in settings)
- Added a default theme
- Changed settings icon color
Update README.md
Update README.md
Bug fixes and cleanup

- Deleted tests and AutoTest.h
- Moved Gui Manager to ui folder
- Renamed Style Manager to Theme Manager and moved it to ui folder
- Fixed segmentation fault caused by not disconnecting signals
- minor bug fixes