* Fix#3957: Properly set filters to defaults on initial load and disable "Clear filters" button if filters are set to defaults
* Reuse resetFilterParameters() in GamesProxyModel constructor, and remove "off" designation for player min/max (as a default of 1/99 is enforced by the UI).
* add opening directory in file browser to linux
this uses QDesktopServices to open the url "file://[location]"
by default this is
"file://$HOME/.local/share/Cockatrice/Cockatrice/pics/CUSTOM"
any distro that has a file browser should have an accompanying mime type
specifying the file handler for the file:// protocol using the
inode/directory mime type
see https://specifications.freedesktop.org/shared-mime-info-spec/shared-mime-info-spec-latest.html
if a user were to have removed their mime database this will not work and
it will fail with nothing but a log message, this would be rare and not
worth checking in my opinion
* make opening directories the same for all oses
* sort headers
* Added keyboard shorcuts to focus and unfocus chat
* Fixed format
* Changed the Esc behavior to work on any QLineEdit in the main Window and ignore shortcut conflicts
* Fixed a conflict with shortcuts
* Configurable unfocus shortcut and format fixes
* minor style fix
* add pauper to the list of checked formats without a short form
l:p remains reserved for pioneer
* throw out weird hardcoded formats
this will at least still work whenever a format gets added
the shorthands are still kept
* Deal with recent Qt methods deprecation
* Use std::sort, std::less instead of qSort/qLess
* Use QFontMetrics::horizontalAdvance instead of ::width
* Use qApp->primaryScreen() instead of QDesktopWidget
* use lambas instead of QSignalMapper
* Use QTreeWidgetItem::setForeground instead of ::setTextColor
* Use QDir::setPath instead of operator=(QString)
* Use QList::swapItemsAt instead of ::swap
* fix error
