ui: Add wallet encryption templates.

tests: Test wallet encryption.

basicswap/basicswap.py

@@ -748,6 +748,9 @@ class BasicSwap(BaseApp):
         if len(self.swaps_in_progress) > 0:
             raise ValueError('Can\'t change passwords while swaps are in progress')
 
+        if old_password == new_password:
+            raise ValueError('Passwords must differ')
+
         # Unlock all wallets to ensure they all have the same password.
         for c in self.activeCoins():
             ci = self.ci(c)