Allow instance admins to add custom CSS that will affect
every page of their instance.
This is done with a new CustomCSS instance setting that
works pretty much exactly like the Users CustomCSS property.
This custom CSS is then requested for every page load.
User styles/themes take precedence over this CSS.
* use apiutil + paging in admin processor+handlers
* we're making it happen
* fix little whoopsie
* styling for report list
* don't youuuu forget about meee don't don't don't don't
* last bits
* sanitize content before showing in report statuses
* update report docs
* love like winter! wohoah, wohoah
* domain allow side effects
* tests! logging! unallow!
* document federation modes
* linty linterson
* test
* further adventures in documentation
* finish up domain block documentation (i think)
* change wording a wee little bit
* docs, example
* consolidate shared domainPermission code
* call mode once
* fetch federation mode within domain blocked func
* read domain perm import in streaming manner
* don't use pointer to slice for domain perms
* don't bother copying blocks + allows before deleting
* admonish!
* change wording just a scooch
* update docs
