Screen: Finish libdc1394 multicamera sync support (Part II).

All hardware trigger control settings implemented and tested:
- Trigger source enumeration, query and select.
- Trigger polarity query and select.
- Trigger mode query and select.
- All sync modes incl. fallbacks: Hardware, Bus, Software.
- Bandwidth query as bonus.
- Improved error handling and also node enumeration.

-> This is relatively well tested and seems to provide resonable
   sync in software mode, where start of master also triggers
   start of slaves by quickly emitting the iso-on commands. About
   < 1 msec error.

-> Both bus sync and hardware trigger sync seem to be sub-msec
   accurate. Microsecond accuracy is expected for hardware triggers,
   but bus sync seems to be also accurate in the low microsecond
   range for cameras of identical model and vendor --> No need for
   external sync cables and trigger inputs if all cameras are identical
   and can be driven from one shared firewire bus (ie. if bandwidth is
   sufficient).

-> Screen for 64-Bit Octave on Linux rebuilt and tested.
-> VideoMultiCameraCaptureDemo updated and tested in various modes,
   also with hardware triggers on identical cameras.
Screen: Allow raw->bayer->rgb and yuv->rgb conversion in libdc1394 video capture.

New optional parameters allow to receive video data in raw8 or mono8
format from camera, ie., raw sensor data, to save firewire bus bandwidth,
and then perform Bayer filtering from raw -> rgb8 in software via libdc's
builtin Bayer conversion algorithms.

Also reworked the yuv->rgb conversion pass to make it consistent with
bayer path.

Also allow return of unfiltered raw8/mono8 sensor data for offline
debayering or self-made debayering (gpu anyone?).

New parameters allow to select debayering algorithm (quality - speed tradeoff)
and bayer pattern if it can't get auto-detected (Auto-Detection only possible
in Format-7 modes due to IIDC limitations).

-> Some dead code removal when we are at it.
-> Screen for 64-Bit Octave on Linux rebuilt and tested.
-> VideoMultiCameraCaptureDemo updated for testing.

-> Both hardware sync and bus sync confirmed to be accurate now.
Screen: Tiny compiler warning fix for libdc1394 video capture.

And some tiny fixes for VideoMultiCameraCaptureDemo.m
Screen: Honor a new optional specialflags setting 'kPsychGUIWindowWMPositioned'

If specified together with kPsychGUIWindow, it tells Screen() to leave
window placement of onscreen GUI windows to the window manager instead
of to Screen.
This will ignore the [left, top, ...] parameter in the 'rect'. Size of
the window will still be defined by the 'rect', but not its absolute
position. The hope is that the window manager will do a better job at
window placement, although testing on OSX 10.9 Mavericks shows that at
least on OSX this hope was not warranted.

-> Screen for 64-Bit Octave and Matlab on OSX rebuilt and tested.
-> Screen on other os'es pending.
-> New flag definition file kPsychGUIWindowWMPositioned.m added.
Screen/Linux: Test WM managed GUI window positioning.

Works more or less.

-> Screen for 64-Bit Octave on Linux rebuilt and tested.
-> VideoMultiCameraCaptureDemo modified for testing this.
-> KDE needs to be switched into "tiling" window placement to get
   good automatic multi-onscreen-window placement this way.
Screen: Change color depth representation in libdc1394 capture.

Encode number of layers instead of bits per pixel, ie.
1 and 3 instead of 8 bits and 24 bits.

-> Preparation for high bit-depth capture support.