JBIDE-17814 - Empty editor is opened instead of Central editor

https://issues.jboss.org/browse/JBIDE-17814
Empty editor is opened instead of Central editor

> why do we need to add to perspective listener and thus run through the list on every perspective switch ?

We use perspectiveChanged when opening an editor (the editorOpen event). 
We can restrict that the fixEditors method is called only for those events, but it is already limited to invalid editorId so that yet another constraint wouldn't mean anything special.

> can't we just run through immediatly or at least remove our self ones we have cleared the editors first ?

Not sure I have understood. A user can open/close the JBoss Central editor in any time so that we can't remove the listener while a window is opened.

As to the window listener, it has been added the perspective listener to be active when a user opens a new window (File>New>Window)