Screen/OSX: Disable VBLIrq/CoreVideo timestamping fallback by default.

Use VBLTimestampingmode 0 by default for the 3.0.12+ series, instead of
mode 1.
This disables use of VBL-IRQ/Shmem fallback on OSX 10.6 Snow Leopard,
as we can’t test it for proper functioning anymore. Might still work
ok, but who knows?
This disables use of Apple’s broken CoreVideo/CVDisplayLink
timestamping on 10.7+. It was unreliable at best, but also causes
random crashes on some setups. This is not fixable by us and i’m sick
of seeing bug reports for it, so disable by default.

Also change recommendation messages to only recommend installation of
the PsychtoolboxKernelDriver for proper timestamping if we are not
running on a Intel GPU, where the kernel driver is disabled for
security reasons.

-> Screen for 64-Bit Octave on OSX rebuilt and tested with
PTKD/non-PTBKD, Nvidia vs. Intel.
-> help texts updated.
Screen/OSX: Improve switchback logic on window close.

Match against MATLAB and Octave. Works better on Octave and Matlab.

Screen for 64-Bit Octave and Matlab on OSX rebuilt and tested.
PsychGPUTestAndTweakGammaTables: Make more robust against buggy graphics drivers.

Move start y-pos of encoder test bar form 10 to 8, so 10-scanlines high
bar goes from -2 to 8. If a graphics driver (e.g., a buggy MS-Windows
driver) has a off-by-one or off-by-two y-pos bug, this should prevent
a black line on top of the screen and make this robust.

Also remove try-catch protection around Screen('LoadNormalizedGammaTable').
Was meant to protect against Windows gamma table upload failure but doesn't,
as Screen will close the window on such an error and code will continue to
run and spill out hundreds of misleading error messages.
ResolutionTest, NearestResolution: Handle multiple outputs per screen on Linux.
SetResolution: Make useable on Linux + single-output x-screen at least.

SetResolution can't handle multiple video outputs per screen
in a reasonable manner, as possible on Linux, where one x-screen
can have multiple outputs.

Make it distinguish 1 vs. multi-output setups and provide
proper behavior on single-output screens. On multi-output
screens on Linux, warn user about limited functionality and
do the best it can.
Screen/OSX: Match refresh rate more lenient for Screen('Resolution').

Our current Screen('Resolution(s)') API only operates with integral
values for refresh rate in Hz, but the underlying OSX functions since
our switch to the 10.6+ SDK return fractional double values. Take
this into account by matching values with a tolerance of up to 1 Hz.

Both Windows and Linux only operate at 1 Hz granularity for setting
nominal Hz, so probably doesn't make much sense to make our API
resolve fractional values.

-> Might fix the "fail to set 120 hz refresh rate" problem experienced
   when testing latest beta on OSX with a 120 Hz video projector.

-> Recompile and test on OSX pending.
Screen/OSX: Fix Screen('Computer') busfreq, cpufreq, usermem reporting.

sysctl() doesn’t report proper values for these properties but simply
makes shit up as 32 Bit values for “backwards compatibility” [quoting
Apple kernel docs]. WTF?!?
sysctlbyname() for the same properties otoh. reports proper values
inside 64-Bit integers. Apparently fixing both system calls going
forward was asked too much from the kernel engineers of the company
that pays insane amounts of attention to detail.

-> Fix this latest crap by Apple.
-> Screen for 64-Bit Octave and Matlab on OSX rebuilt and tested.
Enable Eyelink() support for 64-Bit Matlab on Windows.

Enable build support for 64-Bit Eyelink mex file for Matlab on Windows.
Use pre-release 64-Bit Eyelink SDK for Windows from SR-Research.
-> windowsmakeit64_twisty.m updated with build support.
-> Eyelink.mexw32 32-Bit rebuilt for testing.
-> Eyelink.mexw64 64-Bit for Matlab on Windows initial build.
-> Builds correctly. Don’t know if it really works due to lack of
Eyelink tracker.
Screen('Computer') Add some missing fields to Windows/Linux.

‘gstreamer’ and ‘supported’ support was missing.
Also remove some dead code.