configuration.org: Sort default configurations
Add support for R

Need to fix the locale so the R-sessions support UTF-8.
Configure the latex support in org-mode.

Use latexmk for the building of pdf files. I normally usy microtype,
l2tabu, natbib and lmodern on all latex documents. I don't use a table
of content, at least not by default. Section numbers are rearly used.
Add sparql-mode
Add a mode to support gh-pull requests in magit
Sort list
Add projectile-mode
Add hungry-delete