This is the old way of adding javascript and css assets into dev portal. It was after replaced by 3scale.js and then by 3scale_v2.js, but older dev portals were never updated.

That means there are potentially many dev portals still relying on very outdated dependencies. We need to figure out a way to remove this old dependencies. Options:

a) Send a notification to clients asking to upgrade their dev portals, then remove essential_assets. Pros: no development effort. Cons: need to create a comprehensive upgrade guide OR assist clients individually (if any).

b) Replace contents of essential assets with up-to-date dependencies. Pros: easy to implement. Cons: we can't control old templates, this potentially breaks dev portals.

c) Keep it but warn clients it's using old jQuery. Leave it to them to decide if they want to update. Pros: no effort. Pros: we still host and provide legacy code.