Initial commit

Combines the existing frost-rs, dalek-ff-group, and monero-rs repos into 
a monorepo. Makes tweaks necessary as needed. Replaces RedDSA (which was 
going to be stubbed out into a new folder for now) with an offset system 
that voids its need and allows stealth addresses with CLSAG.

Cargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+
+members = [
+  "sign/frost",
+  "sign/dalek-ff-group",
+  "sign/monero",
+]