update Makefile
Roxygenize
Bump version to 0.0-11.1
Update NEWS.Rd
check for non-factor controls
Bump version to 0.0-11.2
Update NEWS.Rd
new function ml_fit_dss with an implementation very close to the paper by Deville et al. (1993)

implementation in the laeken package
Roxygenize
Bump version to 0.0-11.3
Update NEWS.Rd