note: expose signature field (William Casarin)

Initial note tag support (William Casarin)

fix warnings (William Casarin)

build: set -O1 on debug builds (William Casarin)

pushed to nostrdb-rs:refs/heads/master

http://git.jb55.com/nostrdb-rs/commit/87bf139e699c2493b3242e3d7472acb2cf2683f6.html