MXS-2556 Rename configure -> post_configure

Rename config::Configuration::configure() to
config::Configuration::post_configure(). Latter name makes it
unambiguously clear at what point the function is called.

include/maxscale/config2.hh

@@ -844,11 +844,13 @@ public:
      * Configuration to check any interdependencies between values or to calculate
      * derived ones.
      *
+     * @param params  The parameters the configuration was configured with.
+     *
      * @return True, if everything is ok.
      *
      * @note The default implementation returns true.
      */
-    virtual bool configure();
+    virtual bool post_configure(const MXS_CONFIG_PARAMETER& params);
 
     /**
      * @return The number of values in the configuration.