Ratatosk bugfixes, added polynom parent remote lookup.
Lightened link color in threatened boxes.
Added TaxonDescribers module.

TaxonDescribers wrap APIs that provide taxon descriptions, e.g. Wikipedia,
EOL, etc. We've had similar functionality for a while, but hopefully this will
make it easier to add new ones, and configure which providers are used,
including fallback order.
Changed timeout of TaxonDescribers::Eol.