Patch from issue 975 on behalf of Phil: "Proposition of a patch right Pannel (new visual rendering <-> icons instead of text)"

It moreover better handle workflow changes: no need to restart RT for some options.

rtgui/filepanel.cc

@@ -256,3 +256,7 @@ void FilePanel::loadingThumbs(Glib::ustring str, double rate)
 void FilePanel::updateTPVScrollbar (bool hide) {
 	tpc->updateTPVScrollbar (hide);
 }
+
+void FilePanel::updateTabsUsesIcons (bool useIcons) {
+	tpc->updateTabsUsesIcons (useIcons);
+}