Cleanup and refactor of public plugin API

Improve upon API names, both internal and external, to make it clearer
where methods are located and clarify responsibility.

Add new Makefile target "dev" to create untagged development snapshots.

Bump version for upcoming release.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

plugin.h

@@ -26,6 +26,7 @@
 
 #include <poll.h>
 #include <sys/queue.h>		/* BSD sys/queue.h API */
+#include "svc.h"
 
 #define PLUGIN_IO_READ  POLLIN
 #define PLUGIN_IO_WRITE POLLOUT
@@ -65,7 +66,8 @@ typedef enum {
  * The "dynamic events" discussed in the svc callback is for external
  * service plugins to implement.  However, it can be anything that 
  * can cause a service to need to SIGHUP at runtime.  E.g., acquiring
- * a DHCP lease, or an interface going UP/DOWN.
+ * a DHCP lease, or an interface going UP/DOWN. The event itself can
+ * be passed as an integer @event and any optional argument @event_arg
  *
  * It is up to the external service plugin to track these events and
  * relay them to each @dynamic service plugins' callback.  I.e., to
@@ -80,14 +82,13 @@ typedef struct plugin {
 	char *name;
 
 	/* Service callback to be called once per lap of runloop. */
-	struct plugin_svc {
+	struct {
 		/* Private */
-		int    id;       /* Service ID# to match this service plugin against, set on installation. */
+		int         id;       /* Service ID# to match this service plugin against, set on installation. */
+
 		/* Public */
-		void  *arg;	 /* Optional argument to callback func, set by plugin. */
-		int    dynamic;	 /* Reload (SIGHUP) on dynamic event?  Set by plugin. */
-		int    private;  /* For callbacks to use freely, possibly to store "states", set by plugin. */
-		int  (*cb)(void *arg, int event);
+		int         dynamic;  /* Reload (SIGHUP) on dynamic event?  Set by plugin. */
+		svc_cmd_t (*cb)(svc_t *svc, int event, void *event_arg);
 	} svc;
 
 	/* List of hook callbacks. */
@@ -104,9 +105,6 @@ typedef struct plugin {
 	} io;
 } plugin_t;
 
-/* Used by svc.h */
-typedef struct plugin_svc plugin_svc_t;
-
 /* Public plugin API */
 int plugin_register   (plugin_t *plugin);
 int plugin_unregister (plugin_t *plugin);