* Bulk replaced tabs with spaces
* Bulk removed trailing whitespace from lines
* Replaced c-style comments with c++-style comments in file banners
* Replace nested namespace definitions with single concise definitions (C++17), this keeps the indentation more manageable
* Cleanup ordering and spacing of include directives
* Bulk renaming of header file extensions from '.h' to '.hpp'.
* Update CODING-STYLE.md
* Update target_compile_features from cxx_std_11 to cxx_std_20.
* Refresh .clang-format file. Still needs a lot of tweaking.
The width is determined at runtime based on the largest page in the
QTabWidget. Without this fix, the side panel would annoyingly change
width as you selected the search tab for the first time -- this was
particularly annoying in the de_DE locale.
Jaye Evins