Introduce a struct dcc_ops to contain all functions pointers for a custom DCC type

Modules now must pass a pointer to a struct dcc_ops when calling add_dcc_bind() instead of
a list of function pointers.

include/module.h

@@ -10,7 +10,7 @@
  * if we change the table below, we change this module number to the 
  * current date (YYYYMMDDxx where xx is a serial number).
  */
-#define MODULE_VERSION 2017122001UL
+#define MODULE_VERSION 2018020801UL
 
 #include "struct.h"