Fix implementation of spell check underline styles

The QTextCharFormat documentation said that the used style is based on
QStyle::SH_SpellCheckUnderlineStyle style hint, however in fact the
implementation (drawTextItemDecoration in qpainter.cpp) uses
themeHint(QPlatformTheme::SpellCheckUnderlineStyle) instead since Qt 5
(see commit 1f9ae50457a3750f).

Make the documentation match that behavior, and update QPlatformTheme
to use the correct default value.

Also, switch Cocoa theme to use DotLine, as that is what native macOS
applications use.

Change-Id: I2a6bb3da6c7b0686dca87ed2c251b6abc006123c
Task-number: QTBUG-50499
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@qt.io>

0 files changed, 0 insertions, 0 deletions