- (only) Qt must be provided manually (this is a first step)
- The main change is that VeloView now uses Boost as dynamic lib on
Windows. It was far simpler to do that because at least one other
dependancy (liblas) is using boost as dynamic lib so it would mean
either updating the common superbuild to build *both* or updating
the superbuild to make these dependencies use boost static.

Prepare build with:
cmake c:\VeloView-kwinternal\Superbuild -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo
-DUSE_SYSTEM_qt5=True -DQt5_DIR="C:/Qt/Qt5.10.0/5.10.0/msvc2015_64/lib/cmake/Qt5"
-Dqt_version=5

Then build with:
ninja -jN
(like with make you can go to any previously built target build directory and
run ninja inside of it, to skip passing on dependancies that you now have not
changed)

Remarks:
- forward slashes might be mandatory in Qt5_DIR
- qt_version should be kept for now because paraview 5.4.0 should be
able tolbuild also with Qt4
- disabled unused qtspeech to build with VS Express

To run this build on another machine you will also need to copy some DLLs of
Qt system:
/c/Qt/Qt5.10.0/5.10.0/msvc2015_64/bin/{Qt5Core.dll,Qt5Gui.dll,Qt5Widgets.dll,
Qt5Help.dll,Qt5Network.dll,Qt5PrintSupport.dll,Qt5Sql.dll,libEGL.dll,
libEGLd.dll} ->  "$build_dir/install/bin"

and:
/c/Qt/Qt5.10.0/5.10.0/msvc2015_64/plugins/platforms/{qwindows.dll,qwindowsd.dll}
-> "$build_dir/install/bin/platforms"