Picking fixed. Moving in persp. fixed. Additional gl-material properties added - ambient, specular and
emission parts of light and shininess. Lights added as scene objects - it's possible to move them, change
ambient, diffuse, specular parts of light. Selection box color fixed. Viewer GUI modified.

With new color fetures it's possible to get more interesting materials -
something like metal surface etc (but it's non-trivial to get really
good mixture of colors:) ).


git-svn-id: http://root.cern.ch/svn/root/trunk@10176 27541ba8-7e3a-0410-8455-c3a389f83636