Fix netbeans do not index drupal's files

When you open a drupal project using netbeans > 7.2.1, netbeans won't index files, so we can not go to functions or refactor code.

Here is the way to set up netbeans so that it can recognize drupal's files.

Then you have to delete netbeans's cache, so that it can re-index drupal project:

rm -rf ~/.cache/netbeans/8.0.2