Fix drawing of shadow volume darkcap

Fix long-standing issues with shadow volumes by correcting the
order of triangle vertices for the extruded darkcap.

Use sreMessage instead of printf in sreScene::
CalculateStaticLightObjectLists and add log messages.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Remove unnecessary invalidation of geometry scissors cache

Invalidating the geometry scissors cache is unnecessary, so remove
it. This fixes a crash issue when switching between scissors modes.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Do not mark elephant model as non-closed in demo2

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Update READMEs

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Tweak horizontal velocity/acceleration in demo4

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>