--User changes

-Add a button to swap the pre and post affine values for all selected xforms.

--Bug fixes
 -Remove the ability to change spinner values with +=-=, it was conflicting with other things and added no real value.
 -All file dialog opening in Linux would freeze. No longer using native file dialogs, they are broken.
 -Set default open path to the desktop if there is no settings file present, which will be the case on the first run.
 -Amphibole_Supergroup.ugr palette had an invalid character in two of the palette names.

--Code changes
 -Change some table header padding styles to work with new Qt. Qss reload is required.
 -Ensure the open folder path setting always has a valid string in it before opening a folder.

Source/Fractorium/PaletteEditor/PaletteEditor.cpp

@@ -510,6 +510,7 @@ QStringList PaletteEditor::SetupOpenImagesDialog()
 		m_FileDialog->setViewMode(QFileDialog::List);
 		m_FileDialog->setFileMode(QFileDialog::ExistingFile);
 		m_FileDialog->setAcceptMode(QFileDialog::AcceptOpen);
+		m_FileDialog->setOption(QFileDialog::DontUseNativeDialog, true);
 #ifdef _WIN32
 		m_FileDialog->setNameFilter("Image Files (*.png *.jpg *.bmp)");
 #else