WASHINGTON (AP) — Americans increased their spending in September at twice the rate their income rose, a sign of confidence in the economy.The Commerce Department says consumer spending increased 0.8 percent in September, the best showing since February. Personal income rose 0.4 percent, an improvement from a slight 0.1 percent gain in August and the best gain since March. A pickup in consumer spending helped lift economic growth in the July-September quarter to a still-modest 2 percent annual rate. The economy had grown at a 1.3 percent rate in the April-June period. The slight acceleration in growth was seen as encouraging, but economists are still worried that the economy is stuck in a slow-growth rut.