Move the Monero create to coins/

Includes misc bug fixes

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "sign/monero/c/monero"]
+[submodule "coins/monero/c/monero"]
-	path = sign/monero/c/monero
+	path = coins/monero/c/monero
 	url = https://github.com/monero-project/monero

Cargo.toml

@@ -3,5 +3,5 @@
 members = [
   "sign/frost",
   "sign/dalek-ff-group",
-  "sign/monero",
+  "coins/monero",
 ]

sign/dalek-ff-group/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 
 [dependencies]
 rand_core = "0.6"
+digest = "0.10"
 
 subtle = "2.4"
 

sign/dalek-ff-group/src/lib.rs

@@ -5,6 +5,7 @@ use core::{
 };
 
 use rand_core::RngCore;
+use digest::{consts::U64, Digest};
 
 use subtle::{Choice, CtOption, ConstantTimeEq, ConditionallySelectable};
 
@@ -146,6 +147,14 @@ impl PrimeField for Scalar {
   fn root_of_unity() -> Self { unimplemented!() }
 }
 
+impl Scalar {
+  pub fn from_hash<D: Digest<OutputSize = U64>>(hash: D) -> Scalar {
+    let mut output = [0u8; 64];
+    output.copy_from_slice(&hash.finalize());
+    Scalar(DScalar::from_bytes_mod_order_wide(&output))
+  }
+}
+
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub struct EdwardsPoint(pub DPoint);
 pub const ED25519_BASEPOINT_POINT: EdwardsPoint = EdwardsPoint(constants::ED25519_BASEPOINT_POINT);