With hindsight, I revised decisions made earlier during
this development cycle:
Un-redirectable scriptlets have been removed from
/web_accessible_resources and instead put in the new
/assets/resources/scriptlets.js, which contains all
scriptlets used for web page injection purpose.
uBO will no longer fetch a remote version of built-in
resources.
Advanced setting `userResourcesLocation` will still be
honoured by uBO, and if set, will be fetched every
time at least one asset is updated.