Changes since version 0.1.0
---------------------------

- updated to use PySide6 from PyQt5
- added a working PythonSyntaxHighlighter
- modified to better indicate replace all progress and completeion
- modified editor to use QPlainTextEdit instead of QTextEdit
- modified editor to set tab stops to 4 spaces
- handle dark vs light syntax coloring changes based on Palette.Change events
- now implements the following  case change functions (built-in)
   (all borrowed from calibre and modified to work without icu and in our plugin framework)
    - uppercase
    - lowercase
    - capitalize
    - titlecase
    - swapcase
    - uppercase_ignore_tags
    - lowercase_ignore_tags
    - capitalize_ignore_tags
    - titlecase_ignore_tags
    - swapcase_ignore_tags
