- further fixes of inccorect overflow errors for int (and long on LLP64 systems) * prev commit had bugs * added overflow tests for also int, long, long long (for both, lp64 and llp64) - while at it, fixing a reference leak when not using python with utf8 caching

# example: play sound

lib.winmm <- dyn.load("\\windows\\system32\\winmm.dll")
PlaySoundA <- lib.winmm$PlaySoundA
playsound <- function(path) rdcCall(PlaySoundA$address,"pii)v",path,0,0)
sample <- "c:\\windows\\Media\\tada.wav"
playsound(sample)