Log Message:
Sigil: update to 1.9.1.

Sigil-1.9.1
    Bug Fixes
     - Allow creation of a Windows 7 Legacy Installer to return Sigil to Windows \ 
7 (for now)
     - Completely revamped Find and Replace (yet again) to return most of its
           earlier behaviour for finding next
     - Prevent Find and Replace Count from changing current location
     - Extend spellcheck suggestions to properly handle end of sentence vs \ 
abbreviations
     - Center Image Report File Sizes vertically within their row.
     - Go To Link Or Style will now properly skip leading comments on selectors \ 
in CSS stylesheets
     - ecmascript is considered a core media type for javascript files
     - make URLInterceptor robust when the Book pointer is NULL (has been cleared)

Sigil-1.9.0
    Bug Fixes
     - Update gumbo to follow WhatWG changes for closing br and p tags in \ 
foreign content
     - Fix Saved Search Controls code typo for Tabbed Html Files
     - Plug long existant memory leaks related to Saved Searches that stop after \ 
a match is found
     - More file position of 0 fixes and handle toInt() result failures from N/A \ 
in ValidationResults
     - Fix incorrect copied permissions with AddContentFileToFolder after QFile::copy
     - Fix broken page up / down by key sequence in Repo Log and Automate Log.
     - Fix broken PluginRunner error signal

    New Features
     - Make Validation Results sortable by clicking on column header
     - Add Export All to Validation Results for text or csv output
     - Completely redesign Find Replace and Saved Searches to not overload wrap \ 
when searching multiple targets
         and add "Restart Search" button to make skipping replacements \ 
in Saved Searches easier
     - Update to use the PCRE2 library for regular expression searching
     - Add a new Sigil Preferences settings to disable GPU acceleration for \ 
QtWebEngine/Preview
         to make it easier for Sigil to keep working even with older graphics drivers
     - Add indicator to MainWindow titlebar that indicates if epub in old Sigil \ 
Standard form
     - Support building from source on macOS M1 (arm64) machines
     - Update Windows and Mac embedded python to Python 3.9.9
     - Allow building Sigil with Qt6.2.2+ or Qt5.10+ from the same codebase
     - Speed up "Add Blank HTML" in epubs with huge numbers of files
     - Store and set Epub Zip modification dates where possible
     - Support PySide6 to replace PyQt5 in plugins when building Sigil under Qt6
     - Handle deprecated embedded Python PyEvalInitThreads properly during build
     - Support QUiTool in PySide6 under Qt6 for plugins using .ui files
     - MacOS Python 3.9.9 now now includes TclTK 8.6.12 (no exteral TclTk \ 
package needed anymore)
     - Added Select All Checkbox in Delete Unused Media and CSS (PRs from \ 
@luisparravicini)
     - Add ability to rename classes when editing stylesheet in CV, will rename \ 
in all html as needed
     - SpellcheckEditor now uses LocaleAware sorting vs Case-Insensitive which \ 
did not handle diacritics well
     - Speed up loading of epubs with large numbers of xhtml files by using \ 
concurrency
     - New Hunspell spelling dictionaries based on scowl size 70 for en_GB and en_US
     - Support ending "." in spellchecker wordbreaks for better \ 
abbreviations is dictionary aff supports it
     - Faster CSS stylesheet reformmating that can handle minor errors and still \ 
function