CRAN 1.3.1

Bug fix -- corrects a mistake by which pairwise_Gst_Nei was in fact calculating Hedricks G''st.

Thanks to @thierrygosselin for the PR

CRAN 1.3

New CRAN release 1.3, makes mmod compatible with adegenet 2.0.0 and cleans up a few loose ends (details in NEWS)