docview: various RichTextStyleUnit fixes
docview: various RichTextStyleUnit fixes

- Rename Settings parameter to ASettings. This is to prevent possible
  confusion with the Settings global variable.
- ApplyStyleTag had many issues, applying the style changes to the
  wrong properties. Manyly, styling was applied to the ASettings parameter
  when they should have been applied to the Style parameter.
- Code formatting improvements.

wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI