Screen/GStreamer: Fix camerabin2 videocapture support on GStreamer SDK.

Workaround the continued brokeness of GStreamer-SDK's camerabin2
implementation,
as of 2013.6. We create our own dummy image/jpeg MIME encoding profile
and assign
it to camerabin2 for use with still image capture, despite the fact
that we never
use still image capture. However this is neccessary because by default
camerabin2
has a image/jpeg container profile assigned which doesn't work due to
apparently
missing jpeg muxer plugins (jifmux?) in the SDK. Our MIME profile is
valid but only
defines image encoding, no container, so no muxer plugin needed ->
problem solved.

I don't know if this would work for actual still image capture, but our
purpose here
is only to prevent error handling/error abort during camerabin2 init
from kicking in,
so we don't care.

Tested on OSX with GStreamer-SDK 2013.6 -> Works.
Screen/GStreamer: Make encoding option settings work with camerabin2 video recording.

camerabin2 video recording uses GstEncodingProfile's with loadable
preset settings to define selection and configuration of encoders and
muxers for video recording, so our manual codec option setup doesn't
work. Make it work by:

1. Creating and setting options on all codecs as with camerabin1 or
movie writing operation.
2. Saving codec settings as GstPreset's to filesystem.
3. Loading those presets in encoding profile setup.

Sort of works, except the x264enc encoder has a bug which causes it
to crash if trying to save presets, so it is black-listed and presets
for it need to be provided in a premade file that one needs to copy
to the $HOME/.gstreamer-0.10/presets/ folder. The file is stored in
PsychVideoCapture/GstX264Enc.prs and hard-coded to use fastest encoding
strategy.

However, turned out H264 default setup wasn't the bottleneck. It is
somehow related to audio recording. Video recording without audio
works with reasonable performance, but if audio recording is enabled
performance goes down the drain. Reason completely unknown, so far
tested on OSX 10.7.5.
Screen: Enable latest GStreamer improvements and 64-Bit delay loading.

Recompiled Screen() to take advantage of latest GStreamer improvements.
However, only lightly tested as testing of real videocapture hardware
in the Virtual Machine doesn't work. Only tested with videotestsrc for
synthetic test video stream.

A tiny change to the 64-Bit Windows build script together with the
new 2013.6 SDK now allows delay loading of the DLL's, just as on
32-Bit Windows and on OSX. No more invalid mex file Screen() load
failure if GStreamer SDK is not installed or path not properly set up.

-> Screen for 64-Bit Matlab on Windows rebuilt and tested in Win-7 VM.
Tiny fix for BubbleDemo for short-circuit operator regression.
Bug fix some GLU NURBS functions and make them thereby functional.

Errors in error handling caused the NURBS bits of GLU to be
unuseable. Should fix errors in forum message #16021.

However, gluNurbsCallback() function is unsupported and will
stay that way, due to high effort to implement it and the
deprecated status of the NURBS functions, so no point in
spending more than the minimal effort on them.

However NURBS rendering should work, as the callbacks aren't
needed for standard operations.