reduce sleep time for multiple methods

usw = Usagewatch
usw.batch_refresh # one "long" method with 1 second sleep
usw.uw_cpuused(false) # use data fetched before
usw.uw_cpuused(true) # regular, old way
usw.uw_cpuused # regular, old way

If you need to get more than one time consuming parameters it could be very useful.