Expose last seen time.

Also expose last seen time for token bucket.

userspace/engine/token_bucket.cpp

@@ -84,3 +84,8 @@ double token_bucket::get_tokens()
 {
 	return m_tokens;
 }
+
+uint64_t token_bucket::get_last_seen()
+{
+	return m_last_seen;
+}

userspace/engine/token_bucket.h

@@ -42,6 +42,9 @@ public:
 	// Return the current number of tokens available
 	double get_tokens();
 
+	// Return the last time someone tried to claim a token.
+	uint64_t get_last_seen();
+
 private:
 
 	//