Implement journal replay

Add addprocess event for addtional processes

Add more api process information

runtime.go

@@ -1,6 +1,9 @@
 package containerd
 
+import "github.com/opencontainers/specs"
+
 // runtime handles containers, containers handle their own actions.
 type Runtime interface {
 	Create(id, bundlePath string) (Container, error)
+	StartProcess(Container, specs.Process) (Process, error)
 }