[platform-ui-dev] Changes to PerspectivePresentation

[knut_radloff@xxxxxxx]

As part of fixing bug 10853 (Fast Views should should maximize when the user clicks on the 
title bar) I made two changes to method signatures in the internal class 
PerspectivePresentation. The changes allow for a better, more localized 
fix.
-public zoomIn now takes an IWorkbenchPart instead of a LayoutPane. 
WorkbenchPage is the only caller and calls it appropriately.
-package visible getZoomPart returns an IWorkbenchPart instead of a LayoutPane.

This shouldn't be a problem for anyone since this is not an API class. 
Speak up if you have any concerns. I'll release the changes soon.

Knut