* http://trac.osgeo.org/grass/wiki/Grass7/NewFeatures#Replacedandremovedmodules
* TODO: Merged modules
        r.average: merged into G7:r.statistics, G7:r.statistics2, G7:r.statistics3
        r.bilinear merged into G7:r.resamp.interp
        r.median: merged into G7:r.statistics, G7:r.statistics2, G7:r.statistics3
        r.sum: merged into G7:r.statistics, G7:r.statistics2, G7:r.statistics3
* http://trac.osgeo.org/grass/wiki/Grass7/NewFeatures#Renamedmodules
* TODO: decide what to do with nviz:
    nviz_cmd -> G7:m.nviz.image