expanded options for R CMD build and check to work without latex
expanded options for R CMD build and check to work without latex

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