Add optional fields, custom fields and field options

add a number of optional fields : mood, composer, lyricist, conductor, remixer, bpm
(note that these artist fields do not currently support multi-artists)

rating and playcount can now optionally be saved in the file tag, using FMPS standard

custom fields can be created, currently only custom ratings can be saved in tags

gmusicbrowser.pl

@@ -495,6 +495,12 @@ sub MarkupFormat
 {	my $format=shift;
 	sprintf $format, map PangoEsc($_), @_;
 }
+sub Gtk2::Label::new_with_format
+{	my $class=shift;
+	my $label=Gtk2::Label->new;
+	$label->set_markup( MarkupFormat(@_) );
+	return $label;
+}
 sub Gtk2::Label::set_markup_with_format
 {	my $label=shift;
 	$label->set_markup( MarkupFormat(@_) );
@@ -5137,6 +5143,7 @@ sub PrefDialog
 	$notebook->append_page( PrefAudio()	,Gtk2::Label->new(_"Audio"));
 	$notebook->append_page( PrefLayouts()	,Gtk2::Label->new(_"Layouts"));
 	$notebook->append_page( PrefMisc()	,Gtk2::Label->new(_"Misc."));
+	$notebook->append_page( Songs::PrefFields(),Gtk2::Label->new(_"Fields"));
 	$notebook->append_page( PrefPlugins()	,Gtk2::Label->new(_"Plugins"));
 	$notebook->append_page( PrefKeys()	,Gtk2::Label->new(_"Keys"));
 	$notebook->append_page( PrefTags()	,Gtk2::Label->new(_"Tags"));

gmusicbrowser_list.pm

@@ -3448,7 +3448,7 @@ sub PopupSelectorMenu
 	}
 	my $item1=Gtk2::MenuItem->new(_"Select search fields");
 	$item1->set_submenu( ::BuildChoiceMenu(
-					{ map { $_=>Songs::FieldName($_) } qw/title artist album comment label genre file path album_artist version/ },
+					{ map { $_=>Songs::FieldName($_) } Songs::StringFields(),qw/file path/,},
 					'reverse' =>1,
 					check=> sub { [split /\|/,$self->{fields}]; },
 					code => sub { $self->ToggleField($_[1]); },