Fix default technique matrix name
Set OpenGL attributes after creating the window

Now it actually sets the attributes.
Enable context sharing OpenGL contexts

This flag was missing and was why buffers were not shared
between the loading and rendering contexts.
Create Mesh VAO just before rendering

This enables the rendering thread to create it
instead of the loading thread.
Remove some obsolete virtual function definitions from DefaultTechnique
Cosmetic change
Fix aspect ratio calculation

The division operator took precedence and messed up the calculations.
Only calculate viewport and scissor values once per viewport
Remove unused lua user data map
Render attached meshes using a dummy shader

Used for debugging.
Return after running command-line argument script
Update test script

Load a bigger model and render it with three
different cameras in three different viewports.