Support handling addresses from other networks

A type alias of MoneroAddress is provided to abstract away the generic. 
To keep the rest of the library sane, MoneroAddress is used everywhere.

If someone wants to use this library with another coin, they *should* be 
able to parse a custom address and then recreate it as a Monero address. 
While that's annoying to them, better them than any person using this 
lib for Monero.

Closes #152.

coins/monero/src/wallet/mod.rs

@@ -15,7 +15,7 @@ pub(crate) use extra::{PaymentId, ExtraField, Extra};
 
 /// Address encoding and decoding functionality.
 pub mod address;
-use address::{Network, AddressType, AddressMeta, Address};
+use address::{Network, AddressType, AddressMeta, MoneroAddress};
 
 mod scan;
 pub use scan::SpendableOutput;
@@ -180,23 +180,23 @@ impl Scanner {
   }
 
   /// Return the main address for this view pair.
-  pub fn address(&self) -> Address {
-    Address::new(
-      AddressMeta {
-        network: self.network,
-        kind: if self.burning_bug.is_none() {
+  pub fn address(&self) -> MoneroAddress {
+    MoneroAddress::new(
+      AddressMeta::new(
+        self.network,
+        if self.burning_bug.is_none() {
           AddressType::Featured(false, None, true)
         } else {
           AddressType::Standard
         },
-      },
+      ),
       self.pair.spend,
       &self.pair.view * &ED25519_BASEPOINT_TABLE,
     )
   }
 
   /// Return the specified subaddress for this view pair.
-  pub fn subaddress(&mut self, index: (u32, u32)) -> Address {
+  pub fn subaddress(&mut self, index: (u32, u32)) -> MoneroAddress {
     if index == (0, 0) {
       return self.address();
     }
@@ -204,15 +204,15 @@ impl Scanner {
     let spend = self.pair.spend + (&self.pair.subaddress(index) * &ED25519_BASEPOINT_TABLE);
     self.subaddresses.insert(spend.compress(), index);
 
-    Address::new(
-      AddressMeta {
-        network: self.network,
-        kind: if self.burning_bug.is_none() {
+    MoneroAddress::new(
+      AddressMeta::new(
+        self.network,
+        if self.burning_bug.is_none() {
           AddressType::Featured(true, None, true)
         } else {
           AddressType::Subaddress
         },
-      },
+      ),
       spend,
       self.pair.view * spend,
     )