Devtools is not building .Rd files in the man directory.
git clone https://github.com/az0/mlmeta
cd mlmeta
Rscript -e 'require(devtools);devtools::document()'
This gives
> require(devtools);document('mlmeta')
Loading required package: devtools
Updating mlmeta documentation
Loading mlmeta
First time using roxygen2 4.0. Upgrading automatically...
devtools 1.6.1 (latest from CRAN), R 3.0.2, Ubuntu 14.04