 
      
        documentation improved using new features of roxygen2
fixed namespacing issue which lead to lost labels when subsetting the results of *lply
colwise automatically strips off split variables.
rlply now correctly deals with rlply(4, NULL) (thanks to bug report from Eric Goldlust)
rbind.fill tries harder to keep attributes, retaining the attributes from the first occurrence of each column it finds. It also now works with variables of class POSIXlt and preserves the ordered status of factors.
arrange now works with one column data frames