Updated the code based on the https://github.com/JetBrains/intellij-comm...

...unity/blob/135/platform/lang-impl/src/com/intellij/find/actions/ShowUsagesAction.java file

I uploaded a new jar but kept the same version code.
By the way, the plugin is really nice!!

Signed-off-by: Carlos Sobrinho <carlos@sobrinho.pt>