remove SUPPORTED_GENOMES in annotation_server and replace with list of default genomes from genome build table

[ngehlenborg]

Pivotal Tracker story 46305633 (Nils Gehlenborg - Mar 15, 2013)

[psm3426]

Commit by Psalm Haseley
3e68f13

[finishes #46305633] It doesn't remove SUPPORTED_GENOMES, but it makes sure that it is pulling its contents from the GenomeBuild table. If we actually want to replace all instances of it with [genome.name for genome in GenomeBuild.objects.filter(default_build=True)], that works too, but this seemed the least intrusive (Psalm Haseley - Aug 6, 2013)