permustats gets the name of the statistic and test direction

Fixes also:  item containing the statistic was wrong in permustats.protest
summary.permustats returns only median and critical size of quantiles

For two-sided that is 0.025, 0.5, 0.975, and for one-sided 0.5, 0.95
or 0.05, 0.95.
add densityplot.permustats