Fixed two warnings
Fixed two warnings

/Users/cory.quammen/src/tomviz/tomviz/RecentFilesMenu.cxx:95:40:
warning: unused parameter 'doc' [-Wunused-parameter] void
save_settings(pugi::xml_document& doc)
                                  ^

/Users/cory.quammen/src/tomviz/tomviz/RecentFilesMenu.cxx:38:18:
warning: unused variable 'MAX_ITEMS' [-Wunused-const-variable]

static const int MAX_ITEMS = 10;
                 ^

OpenChemistry/tomviz,OpenChemistry/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,mathturtle/tomviz