lib, gapi: Next method of GAPI should generate first event

This puts the generation of the initial event into the Next method of
the GAPI. If it does not happen, then we will never get a graph. This is
important because this notifies the GAPI when we're actually ready to
try and generate a graph, rather than blocking on the Graph method if we
have a long compile for example.

This is also required for the etcd watch cleanup.

gapi/gapi.go

@@ -25,10 +25,11 @@ import (
 
 // Data is the set of input values passed into the GAPI structs via Init.
 type Data struct {
-	Hostname string // uuid for the host, required for GAPI
-	World    resources.World
-	Noop     bool
-	NoWatch  bool
+	Hostname      string // uuid for the host, required for GAPI
+	World         resources.World
+	Noop          bool
+	NoConfigWatch bool
+	NoStreamWatch bool
 	// NOTE: we can add more fields here if needed by GAPI endpoints
 }