[vtkusers] VTK build fails to link to swscale

[John Haiducek]

When I build VTK I get errors like this:

Linking CXX executable ../../../../bin/QVTKCxxTests
../../../../bin/libvtkIO.so.5.2.1: undefined reference to `sws_freeContext'
../../../../bin/libvtkIO.so.5.2.1: undefined reference to `sws_scale'
../../../../bin/libvtkIO.so.5.2.1: undefined reference to `sws_getCachedContext'
collect2: ld returned 1 exit status
make[2]: *** [bin/QVTKCxxTests] Error 1
make[1]: *** [GUISupport/Qt/Testing/Cxx/CMakeFiles/QVTKCxxTests.dir/all] Error 2
make: *** [all] Error 2

The error goes away when I add -lswscale to my CXXFLAGS, but surely
there's a better way to fix it?

John Haiducek