GARD deactivation

[hoelzer]

I am thinking about making GARD an optional step or at least add some parameter to disable GARD. It's simply a time-consuming step. Although, recombination testing is important when looking for positive selection. 

But when a user has a rather large input FASTA and is not at all interested in recombination detection it would be nice to have some functionality to deactivate GARD.