Add an argument to inferGenotype to use the bayesian method

[ssnn]

Most of the genotype inference (inferGenotype) function is kept and only few Bayesian code fragments are added. It makes sense to add an argument to the original function to use the bayesian method. Opinions @javh?

[Jason Vander Heiden]

Up to you. If it generates the same output from the same input, then I think an argument is appropriate. If the input/output differ, then I'd make it a separate function.

[ssnn]

There are only a few arguments that differ in the input. In the output that bayesian function adds some extra columns. I asked @skleinstein and we decided to keep the functions separated.