BUG: Update VTK project to fix build using Xcode 5.1.1

This commit updates the Slicer VTK project to include the following
patch cherry-picked from current VTK development branch.

Thanks to Hans Johnson for suggesting the backport.

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Author: Sean McBride <sean@rogue-research.com>
Date: Thu Feb 13 14:26:42 2014 -0500

Removed -fobjc-gc from VTK_REQUIRED_OBJCXX_FLAGS

There are 3 memory management models in Cocoa,
chronologically by introduction: MRR, GC, ARC.
VTK supports the first two.
GC is now deprecated however, and Xcode 5.1 will
no longer even build GC code.  Therefore
removed the -fobjc-gc option as a default.
(It built the libraries as both MRR and GC
compatible, which was convienent for library code.)

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git-svn-id: http://svn.slicer.org/Slicer4/trunk@23338 3bd1e089-480b-0410-8dfb-8563597acbee