Improve handling of errors in lua functions and speed up calls. (#1427)

src/PercentageDisplay.cpp

@@ -177,8 +177,7 @@ void PercentageDisplay::Refresh()
 				Lua *L = LUA->Get();
 				m_FormatPercentScore.PushSelf( L );
 				LuaHelpers::Push( L, fPercentDancePoints );
-				RString Error= "Error running FormatPercentScore: ";
-				LuaHelpers::RunScriptOnStack(L, Error, 1, 1, true); // 1 arg, 1 result
+				LuaHelpers::RunScriptOnStack(L, 1, 1); // 1 arg, 1 result
 				LuaHelpers::Pop( L, sNumToDisplay );
 				LUA->Release(L);
 			}