R: added cairo dependency

Closes #587, closes #613.
Armadillo: update to 4.000.0

Closes #614.
OpenNI: Modify samples' directory

Closes #607.
Armadillo: Remove boost dep and add arpack.

Closes #619.
idcoefs 2.1.1: New Formula

Compute the condensed identity coefficients for pairs of individuals.

Closes #610.