refactoring: remove dead code.

Signed-off-by: Kim Kulling <kim.kulling@googlemail.com>
Merge branch 'master' of https://github.com/kimkulling/zfxce2
refactoring:
- rename demos to examples.
- rename IRenderTest to AbstractRenderTest.

Signed-off-by: Kim Kulling <kim.kulling@googlemail.com>