When windows are closed, they should removed from the windowList
When a WorkspaceManager is destroyed, it should also call the destroy method in all the windows in the _windowList. This will disconnect them
There's no need to store GlobalManager in a variable in line 265. This stops the assignment to undeclared variable workspaceManager warning from happening
Merge pull request #6 from erickpires/master

Better solution for the issue when a maximized window is closed