Move version entry point into MODULE_INFO

The MODULE_INFO can easily hold the version information of the
module. This removes the need for a explicit version entry point.

include/maxscale/modinfo.h

@@ -85,6 +85,7 @@ typedef struct
     MODULE_STATUS   status;
     MODULE_VERSION  api_version;
     const char     *description;
+    const char     *version;
 } MODULE_INFO;
 
 MXS_END_DECLS

include/maxscale/modules.h

@@ -41,15 +41,13 @@ 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 */
+    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;
 
 /**