Move R code to separate files

This commit moves the embedded R code outside the document
and then uses the fancyvrb package to display it inline. The
book no longer uses knitr and this is hopefully a more
approachable setup.
Convert bootstrap code from R to Julia

This commit translates the bootstrap code from R to
Julia. I'm going to change all of the code to Julia
eventually.
Convert model selection code to Julia

This commit translates the code for the model selection chapter
to Julia from R.
convert code snippit in LRT discussion to Julia
Update NEWS file with Julia progress