updated due to the change of an IVAR of vtkStreamTracer
     fixed a problem with vorticity computation,
     replaced TIME_UNIT with LENGTH_UNIT,
     renamed ConvertToTime() to ConvertToLength(),
     removed some redundant functions,
     updated vtkStreamTracer's UI panel,
     updated vtkStreamTracer-related test source files, and
     updated three baseline images

====Please update the following 10 files====

==== Changes to ParaView-specific files ====
ParaView3\Servers\ServerManager\Resources\filters.xml

==== Changes to CTest (involving VTK & ParaView) files ====
ParaView3\VTK\Graphics\Testing\Tcl\streamTracer.tcl
ParaView3\VTK\Graphics\Testing\Tcl\TestMultiBlockStreamer.tcl
VTKData\Baseline\Graphics\streamTracer.png
VTKData\Baseline\Graphics\TestMultiBlockStreamer.png
VTKData\Baseline\Parallel\TestPStream.cxx.png

==== Changes to VTK/ParaView common files ====
ParaView3\VTK\Graphics\vtkStreamTracer.h
ParaView3\VTK\Graphics\vtkStreamTracer.cxx
ParaView3\VTK\Parallel\vtkTemporalStreamTracer.cxx
ParaView3\VTK\Parallel\vtkDistributedStreamTracer.cxx