Version 3.1.0.9000 (not released on CRAN)

v3.1.0.9000

deleted cran-comments

CRAN version 3.1.0

v3.1.0

speed improvement

CRAN version 3.0.0

v3.0.0

deleted cran-comments

CRAN version 2.0.0

v2.0.0

add some stopifnot

CRAN version 1.0.1

v1.0.1

prepare CRAN release

CRAN version 1.0.0

v1.0.0

CRAN release