Extract allele frequency from fetched uniprot variants info

[Tom Goddard]

Would be interesting to see allele frequency and minor allele frequency in fetched uniprot variants data. These can be two more scores in addition to the polyphen2 and sift pathogenicity scores.

[Tom Goddard]

Done.

Trying to display allele frequency for opioid receptor P35372 together with pathogenicity data on one heatmap revealed problems. The heatmap uses the same colormap for each score and the frequency data wants colors blue, white, red around 1e-5, 1e-4, 1e-3 while the pathogenicity wants 0, .5, 1.

Another heatmap problem was that allele frequency was not available for some residues where pathogenicity was (e.g. 1-4) and showing allele frequency caused the heatmap to omit those residues.