[nbui] Collapse all button for files/projects views

[Mitch Claborn < >]

http://netbeans.org/bugzilla/show_bug.cgi?id=113278

Please vote for this if you find it a good idea.  I do some development 
in Eclipse, for Android apps. When in Eclipse I use this feature 
constantly, and miss it severely when in NetBeans.

One way to accomplish it in the UI would be to put a small toolbar at 
the top of these views, which could have the button for collapse all, 
and potentially other useful functions.  Right click in the white space 
would also be good - and easier to implement since there is already a 
context menu there.

Any thoughts?

Mitch