Rename MODULE_INFO to MXS_MODULE

The MODULE_INFO is now the main object which is used by modules to convey
information to the MaxScale core. The MXS_MODULE name is more apt as it
now contains the actual module definition.

The old MODULES structure was moved into load_utils.c as an internal
implementation and was renamed so that it is not confused with the new
MODULE structure.

include/maxscale/modules.h

@@ -39,17 +39,6 @@
 
 MXS_BEGIN_DECLS
 
-typedef struct modules
-{
-    char    *module;       /**< The name of the module */
-    char    *type;         /**< The module type */
-    char    *version;      /**< Module version */
-    void    *handle;       /**< The handle returned by dlopen */
-    void    *modobj;       /**< The module "object" this is the set of entry points */
-    MODULE_INFO *info;     /**< The module information */
-    struct  modules *next; /**< Next module in the linked list */
-} MODULES;
-
 /**
  * Module types
  */