Addition of the module info structure to allow module information to

be extracted from the modules.

This gives a way to verify the API that the module provides as well
as the version of that API. The hope is that this will make it possible
for MaxScale to detect out of date plugins and either adapt to use them
or reject loading them.

Also added the ability to set a release state on a per module basis.
This allows for production ready and non-production ready plugins to
be identified.

server/include/router.h

@@ -78,6 +78,13 @@ typedef struct router_object {
         uint8_t (*getCapabilities)(ROUTER *instance, void* router_session);
 } ROUTER_OBJECT;
 
+/**
+ * The router module API version. Any change that changes the router API
+ * must update these versions numbers in accordance with the rules in
+ * modinfo.h.
+ */
+#define	ROUTER_VERSION	{ 1, 0, 0 }
+
 typedef enum router_capability_t {
         RCAP_TYPE_UNDEFINED    = 0,
         RCAP_TYPE_STMT_INPUT   = (1 << 0),