BUG: Update OpenIGTLinkIG to fix issues in sending PolyData.

Fixes 0004095

$ git shortlog 3ad1f67..6e297b7 --no-merges
Christian Askeland (3):
BUG: openigtlink/OpenIGTLinkIF#54 Color not supported in vtkImageData->igtl::ImageMessage.
BUG: Fixed openigtlink/OpenIGTLinkIF#55 Segfaults in encode/decode vtkPolyData
BUG: Fixed openigtlink/OpenIGTLinkIF#56 vtkPolyData encoding reuses data from last encoding.

Junichi Tokuda (1):
Instead of creating a new igtl::PolyDataMessage in vtkIGTLToMRMLPolyData::MRMLToIGTL()
to clear the content of OutPolyDataMessage, call igtl::PolyDataMessage::Clear().
igtl::PolyDataMessage::Clear() will be reimplemented based on the discussion for
Issue openigtlink/OpenIGTLinkIF#57.

From: Junichi Tokuda <tokuda@bwh.harvard.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24802 3bd1e089-480b-0410-8dfb-8563597acbee