Fix building against an installed SimpleITK.

SimpleITKConfig.cmake SimpleITK_LIBRARIES does not appear to be set correctly
yet, though -- missing SimpleITKBasicFilters{0..n}.  Likely due to the use of
the CACHE INTERNAL, but more investigation is required.
Build SimpleGaussian.cxx.
Fix OpenCV bridge example linking errors.
Update dataDir for ISBI VM.
Instructions for running the Demo. Remove presentation references.

Since we will not have much time to talk with the presentation.
Fix up the BasicTutorial examples.