Use same CMakeLists.txt file for the core build (if BUILD_TEST=ON) and install of the C++ examples and the install-tree build of the C++ examples.  
Use same CMakeLists.txt file for the core build (if BUILD_TEST=ON) and
install of the C++ examples and the install-tree build of the C++ examples.  

As a byproduct of this merging of two different build capabilities within
the same file, the core build of the C++ examples now includes the "special"
C++ example, qt_example.


svn path=/trunk/; revision=10209

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot