code on Nostr: use nostr.build api v2 with optional nip98 support (Fishcake) add function to create ...

use nostr.build api v2 with optional nip98 support (Fishcake)
add function to create nip98 http authorization header (Fishcake)
add nostr event 27235 (nip-98) (Fishcake)

pushed to damus:refs/heads/master
http://git.jb55.com/damus/commit/c464a26151046e17cd469f390a3212b8af1c9c8e.html