Explore the possibility to create a SetBase package

[llrs]

The license seem to allow it.

I should probably contact nevertheless with Thomas and Martin about creating this package. And see if it is possible/recommended to make GSEABase and GeneSet class depend on a Set class. I would like to avoid having a SetColour class or the code to mapIds as it might not be useful for others
sets does not create a new class but hierarchicalSet does a new S3 class.
The package should go onto CRAN.

[llrs]

See package llrs/BaseSet and related