File handle leaks with Groovy verticles on Windows

[fbricon]

Originally reported at https://bugs.eclipse.org/bugs/show_bug.cgi?id=432546

I tried to make a module out of the Groovy http server verticle (https://github.com/vert-x/vertx-examples/blob/master/src/raw/groovy/http/Server.groovy), with a mod.json containing :
{
"main": "Server.groovy",
"auto-redeploy": true
}

On windows 7, Oracle JDK 7u45 or 8, when I modify the content of Server.groovy, the file is locked by vertx (2.0.1.Final or 2.1.RC3) so I get an error when saving it. Weirdly enough, vertx detects something has changed, but still, the new content is not served. The lock disappears after some time, but the delay seems random. Corresponding java implem. doesn't block file updates.

Test mod at https://github.com/fbricon/bug432546

Screencast showing how bad it is : http://screencast.com/t/MySckzdFu