1) Temporary _Light and _Material classes are replaced. Added ability to set Light...

1) Temporary _Light and _Material classes are replaced. Added ability to set Light and Material to VE (like VE::SetMesh). 2) 3D-Picking features are added to VE's HitTest and GetChildAt. 3) Added Scene class: loading meshes, materials and texture file names from COLLADA. 4) Added DefaultShaderProgram, existed predefined shaders now are instacies of DefaultShaderProgram class; for RenderManager there is no difference between _CustomShader and _DefaultShader objects - it works with base class _GlShaderProgram

Change-Id: I2412e2a0d68a127e8270b84c2d1a04f7afa7f750
Signed-off-by: k.zverev <k.zverev@samsung.com>