Merge pull request #63 from philmikejones/docs

merge pkdown docs

Merge pull request #58 from philmikejones/release

merge release

Merge pull request #29 from philmikejones/cran-comments

Resubmit

Merge pull request #26 from philmikejones/release

prepare initial cran release

Merge pull request #16 from philmikejones/rake

add Rmd readme

Merge pull request #14 from philmikejones/examples

bump version