Fix default shaders code

Return required per-pixel material parameters as defined in
GeometryBuffer.h comment.
Update project description

Why have I messed it up in the first place?
Add UniformBuffer class
Update empty ImageTexture format

Use RGB16F, floats will be clamped to 0.0f..1.0f otherwise.
Update exception messages to be raised from Light
Implement lighting render pass

Render frame for every light on scene, blend with ambient-lighted scene.
Add diffuse lighting shader code.
Update example code with lighting enabled
Fix Object, SceneManager rotation/translation/scaling
Add test classes
Update CMakeLists.txt, add test target
Fix object attachement

Add object into node's lights/entities cache only if previously
added into objects cache.
Fix vertex normals translation

Ignore rotation and scaling matrices.
Add copyright to CMakeLists.txt
Update Graphene and Window classes

Rename Graphene class to Engine, equally named namespace and class emerged
some problems in example application code.
Split mouse handler into two (motion + buttons), add a separate hanled for
'idle' event (message queue drained).
Add default handler for 'quit' event.
Add usefull methods like getKeyboardState() to Window class (see diff).
Update example application

Update code for recent library changes.
Ass FPS-alike camera movement.
Describe GRAPHENE_TEST option in README
Fix blender exporter

Add default material if nothing is assigned to object.
Re-calculate normals after transformation matrix applied.
Update Light class

Rename innerAngle to angle, outerAngle to blend.
Note: blend parameter semantics is now as in blender's spot light
blend parameter.
Update example application

Increase player speed multiplier to 8.0f.
Set test light energy value to 0.5f.
Finalize Phong reflection model

Add ambient intensity to geometry buffer, use it in light equasions.
Implement diffuse and specular highlights.