add easyconfigs for Circos + deps, including Perl update

depends on https://github.com/hpcugent/easybuild-easyblocks/pull/380 and  https://github.com/hpcugent/easybuild-easyblocks/pull/425 (sort of)
add ```'http://search.cpan.org/CPAN/authors/id/E/ET/ETHER```