title: why there a .lock-wscript file after I run node-waf build
body: <p>after I run <code>node-waf configure</code> and <code>node-waf build</code>, a <code>.lock-wscript</code> show in my folder, what's this? even I run <code>node-waf clean</code>, it still there. shall I keep it or remove it?</p>