MDF creation error with scientific notation

[DanHupalo]

Hi, I encountered an error when running a VCF with a populated INFO line. Specifically MDF creation crashed when the field 'AF=' was present in the INFO line with an allele frequency that is reported in scientific notation ex: ;AF=3.6808e-05; .

Changing the allele frequency to its decimal equivalent of 0.000036808 resolves the issue, but as allele frequencies are reported in scientific notation very frequently, it may make sense to add the ability to handle scientific notation.