Zephyr coin support

Solo mining will require `--coin Zephyr` in command line, or `"coin": "Zephyr",` in `pools` section of config.json

src/base/crypto/Coin.h

@@ -39,6 +39,7 @@ public:
         KEVA,
         RAVEN,
         WOWNERO,
+        ZEPHYR,
         MAX
     };