Do a little tidying/normalization.
Do a little tidying/normalization.

This does two things:
 * sets indentation to 4 (egads!)
 * makes devtools use uniform, with a note that it might be made optional.

qinwf/r-travis,hadley/r-travis,qinwf/r-travis,eddelbuettel/r-travis,robzhu/r-travis,hadley/r-travis,robzhu/r-travis,craigcitro/r-travis,craigcitro/r-travis,eddelbuettel/r-travis