Minor alterations to header/footer
Alter allele frequency displays

Add ability to display OtoSCOPE v4 MAF data. Alter display for EVS MAF data
by adding an "All" frequency. Alter display for 1000 Genomes by
combining 19 smaller populations into  4 super-populations plus an "All"
population.
Add loading icon for genes page and fix allele frequency error

When sorting genes by first letter there is now a loading icon for long
page loads. The divide by zero error was also fixed when loading
allele frequencies.