retro-compat with boost 1.44
minor fix in cmakefiles.
added FindGLViewer.cmake
added imguiSlider with possibility to explicit number of digits.
added set_backColor()
boost compat.
added plot tool.
added graphical scene for handling graphical objects & added lighting.
added composite graphical object.
added visible attribute to graphical objects.
added graphical polyline and major naming convention unification.
fix last commit.