PsychHID/Linux: Change default debug level for libusb to zero = silence.

So far we had highest level of verbosity by default (3), which caused
significant spilling of meaningless warning and error messages which
didn't point to any real problem.

Now we default to silence. Usercode can still enable verbose debug
output by calling PsychTweak('LibUSBDebug', verbose) with a verbose > 0
level before first invocation of PsychHID, should there be a need
for low-level debugging of problems. The function influences all uses
of libusb-1.0 based mex files loaded after the PsychTweak() call, e.g.,
also PsychKinectCore, some libdc1394 usb video capture, etc.

-> PsychHID mex file for 32/64-Bit Matlab/Octave on Linux rebuilt.
-> PsychTweak() extended.
DaqScanDumbTest: A very bare-bones test of DaqAInScan() et al.
Add text mode fallback to ConfirmInfo() and TwoStateQuery().

Fix the two most useless and misguided functions in Daq toolbox.
They would otherwise fail on current Octave or Matlab in -nodesktop
mode.

-> Makes DaqFind not fall over if no Daq can be found.
DaqDeviceIndex(): Remove the "USB-1408FS untested" warning.

It is tested now and works at least on Linux, Windows-7 and
32-Bit OSX as far as my limited tests went.
DaqTest: Disable EEPROM read/write tests by default.

Having these on seems to be bat-shit crazy to me! Even
if there is only a small chance of bricking the device
this way, it is irresponsible default behaviour!

DaqTest gets about half-way through with the USB-1408FS,
so it is not fully adapted to test that device.
Screen for 32-Bit Matlab on OSX: Final recompile before end-of-life.

Now synced to state of current beta.
Screen: Fix bug in imaging pipeline setup for multi-sampled depth & stencil renderbuffers.

In the codepath with MSAA on and 3d depth & stencil renderbuffers, init
failed due to uninitialzied twidth and theight variables!
-> Fixed.
Screen: Improve error handling for GStreamer movie playback.

If plugin creation for playbin2 or appsink fails, abort early and with
a hopefully more helpful error message hinting at a GStreamer
installation problem, e.g., missing or defective gst-plugins-base.
Screen mex files rebuilt for all platforms except 32-Bit Matlab OSX.

-> Improved error handling for GStreamer.
-> Bugfix for imaging pipeline + multisampled depth renderbuffers.