Apply https://gitlab.com/relan/fennecbuild/-/blob/master/fenix-liberate.patch
at edac9bd4083644ae0b8ae04e6af719892f05ee3a
License sign-off from author "relan" in
https://gitlab.com/relan/fennecbuild/-/issues/4#note_404430753
"Note that fenix-liberate.patch is a copypaste from various projects under
Apache 2.0 and MPL 2.0. I've made only trivial changes and it makes sense to
distribute them under MPL 2.0 or Apache 2.0, not AGPL.
I think I need to add license headers to all new files added by the patch."
We can pick up additional license headers if and when they're added by relan.
Almost all the code is trivial, probably-uncopyrightable stubs.
We might be supposed to put more info in the licenses screen in the app, which
I'm keeping, for some of these, but I'm not sure how.
