added Imports
no more import(dhstools)
call to stringr fn now explicitly uses stringr namespsace
updated docs...
no more explicite library(plyr)
updated to accommodate new return format for draw.degrees.fn from
estimate.degree.distns
call to Curry now explicitly specifies functional namespace

ie, it uses functional::Curry(...) instead of just Curry(...)
load functional library before package tests
ignore the .Rcheck/ directory created by R CMD CHECK