KukaPlayer: Fix assignment of movie channels in Anaglyph modes.

Assignment of movie stereo channels to projectors needs to be
inverted in dual-projector anaglyph modes as well, not only
for single-projector mode.
KukaPlayer: Try to obey nominal movie framerate in standalone mode.

If working standalone, without a UDP client to drive the playback
timing, try to play back at correct movie fps, as encoded in movie.
KukaPlayer: Hold calibration grid testmovie until keystroke.

The special movie with calibration grid only has 3 frames.
To make it useable, let the last movie frame hang onscreen
until keypress.
KukaPlayer: Fix lag of 1 videoframe for stereo display modes.

Turns out some of our optimizations backfired.

Ordering of draw commands of movie image textures and text
into offscreen windows wrt. actual 3D rendering of those offscreen
windows into the 3D scene was set up to minimize changes of
drawing targets - and thereby potentially expensive OpenGL pipeline
flushes.

This backfired when we had to switch assignment of eye views to
to target stereo buffers for rendering of content in stereo presentation
mode, instead of mono presentation mode. The ordering caused the right
eye view to source from an offscreen window that wasn't yet updated with
current frame content. Result was an offset of 1 movieframe between
left projector and right projector stereo output!

At least this explains why we got stereo percepts from a purely
monoscopic movie the other day whenever the movie showed large
scale movement -- We managed to involuntarily implement the
Pulvrich effect in software! The right eye got a 16.6 msecs time-delayed
version of the same image content wrt. the left eye -- Movement
causes apparent disparity and pseudo-stereo.

Now fixed this by always rendering both frames (left and right eye)
of a given full movie frame into both offscreen windows first, then
performing the left-/right-eye 3D rendering pass that sources from
both offscreen windows. Lag fixed, at the cost of probably slightly
increased pipeline flushing overhead. However, the performance penalty
seems to be small enough to not be measureable -- on the order of
run by run performance variation.

Additionally added a bit more debug output: We now draw the current
movie framecount if text drawing is on, so one can see immediately
in slow motion or by interrupting the script if both counts match, ie.,
if the stereo streams are in sync.

Also add a new flag doSpeedTest, which if set to 1, will enable the
rendering speed benchmark which renders and flips as fast as possible,
via synchronous flips, without sync to retrace of OpenGL bufferswaps.
KukaPlayer: Add support for normal playback with sound output.

If doMovieSoundPlayback=1 is set, play movie without prebuffering
(async flags 0) at normal forward speed, with playback of audio
track of movie (if any) enabled.
KukaPlayer: Use half-color gamma corrected rendering by default.

Use mode 2, "half-color" anaglyph rendering by default, if anaglyph
rendering is used. Additionally perform gamma correction with a
0.5 gamma on the red channel to boost low intensities. This gives
better results.

Also, disable 'flip' ifi throttling if standard playback with sound
is active. The GStreamer engine already takes care of framerate control
and audio-video sync, no need for us to mess with it on top of it.

This version shows good results in dual-projector advanced anaglyph
mode on the Kuka setup with different well encoded test movies.
KukaPlayer: Disable sound by default, choose good default movie.

Disable audio playback and GStreamer timing control by default,
just as in experiment conditions.

Choose the latest good experiment movie by default, if no
moviename provided.

This release provides overall good quality with anaglyph mode,
both single- an dual-projector, as well as mono projection.

InfiTec mode is so far untested.