MXS-1929: Take SFilterDef into use

The service now uses a std::vector<SFilterDef> to store the filters it
uses. Most internal parts deal with the SFilterDef but debugcmd.cc still
moves raw pointers around (needs to be changed).

include/maxscale/filter.h

@@ -225,16 +225,6 @@ typedef struct mxs_filter_def
 {
 } MXS_FILTER_DEF;
 
-/**
- * Lookup a filter definition using the unique section name in
- * the configuration file.
- *
- * @param name The name of a filter.
- *
- * @return A filter definition or NULL if not found.
- */
-MXS_FILTER_DEF *filter_def_find(const char *name);
-
 /**
  * Get the name of a filter definition. This corresponds to
  * to a filter section in the configuration file.

include/maxscale/service.h

@@ -146,8 +146,6 @@ typedef struct service
                                         * when querying them from the server. MySQL Workbench seems
                                         * to escape at least the underscore character. */
     SERVICE_REFRESH_RATE *rate_limits; /**< The refresh rate limits for users of each thread */
-    MXS_FILTER_DEF **filters;          /**< Ordered list of filters */
-    int n_filters;                     /**< Number of filters */
     int64_t conn_idle_timeout;         /**< Session timeout in seconds */
     char weightby[MAX_SERVICE_WEIGHTBY_LEN]; /**< Service weighting parameter name */
     bool retry_start;                  /**< If starting of the service should be retried later */