Oil prices closed at a three-week high on Wednesday, boosted by signs of strong demand for crude products and renewed commitments by major oil producers to rein in production.  Light, sweet crude for May delivery gained $1.14, or 2.4%, to $49.51 a barrel on the New York Mercantile Exchange, up three of the past four sessions. Brent crude, the global oil benchmark, rose $1.09, or 2.1%, to $52.42 a barrel.  On Wednesday, data from the U.S. Energy Information Administration showed a larger-than-expected decline in gasoline and distillate stocks, while refiners processed crude oil at a higher rate. Crude inventories rose 900,000 barrels in the week ended March 24, lower than the average forecast from analysts and traders surveyed by The Wall Street Journal.