Fixed bugs that were caused by the renderer overhaul.
Adapted Lua core scripts to new render system.
Added notes on another scenario idea.
Adapted example objects to new render system.
Implemented render layers.

Which where called render stages earlier.

Closes 44
Updated JSON exporter.
Enhanced render layers and their Lua bindings.
Moved example package in own repository.

See https://github.com/henry4k/apoapsis-example

Closes #45
Added licence notes.
Added licence text. (Amend to previous commit.)
Changed the slogan a bit.
Updated lua-mock.
Updated lua-mock once again.
Fixed bug in lua-mock.

Damn.
Adapted tests.
Added more tests.
Merge branch 'master' into feature/lua-tests
Adapted some tests.