Remove R/PlotStereoMap.R and man/PlotStereoMap.Rd because it was causing compilation issues + come back to old PlotEquiMap version + addition of the abind library on the dependencies

Virginie's comment + bugfixes(index definition, wrong defeinition of the difference distribution, return arguments)

bugfixe: reverse order of the confidence interval, lower was in position 3 and higher was in position 1