prepare CRAN release 0.9.0 (#1)

* precalc tau in print/summary

prevents asynchronous printing of output

* enable quasi MC for dep_measures()

* set version to 0.9.0

* update vignette

* update README

* update NEWS

* update pkgdown docs

* update vignette

* update vignette in inst/doc

include pkgdown

has been on gitignore

CRAN submission 0.8.0