opaque error when incompatible vcf file is loaded

[RichardJActon]

MutantSets assumes the presence of certain things in the INFO column of the vcf output generated by freebayes and is not compatible with the output of the mimodd vcf file. Because both vcf files are generated by the galaxy pipeline, (mimodd produces a vcf but only the mimodd deletion calls, .gff, are used in MutantSets). This has resulted in some confusion as when the mimodd vcf is loaded into MutantSets it does not throw an informative error but silently fails to load the variant table / apply filters properly.

• Add an error message when the vcf has missing fields
• Update the documentation to make it clearer which .vcf to use (easy to miss in step 8 of the vignette)