Bump to 6.0.43, use go generate

Also moved fetching of JSON information to Go for cross-OS usage.

fields/6.0.43/SettingSuperSmtp.json

@@ -0,0 +1,11 @@
+{
+  "enabled": "true|false",
+  "host": "",
+  "port": "[1-9][0-9]{0,3}|[1-5][0-9]{4}|[6][0-4][0-9]{3}|[6][5][0-4][0-9]{2}|[6][5][5][0-2][0-9]|[6][5][5][3][0-5]|^$",
+  "sender": "",
+  "use_auth": "true|false",
+  "use_sender": "true|false",
+  "use_ssl": "true|false",
+  "username": "",
+  "x_password": ""
+}