Add SSL support for created servers

Servers created at runtime can now be configured to use SSL. The
configuration is only possible if the server is not in use.

The `alter server` command in maxadmin now takes a list of `key=value`
strings. This allows the user to define multiple alter operations with one
command.

include/maxscale/server.h

@@ -245,6 +245,18 @@ extern bool server_create(const char *name, const char *address, const char *por
                           const char *protocol, const char *authenticator,
                           const char *options);
 
+/**
+ * @brief Serialize a server to a file
+ *
+ * This converts @c server into an INI format file. This allows created servers
+ * to be persisted to disk. This will replace any existing files with the same
+ * name.
+ *
+ * @param server Server to serialize
+ * @return False if the serialization of the server fails, true if it was successful
+ */
+bool server_serialize(const SERVER *server);
+
 /**
  * @brief Destroy a server
  *