PsychtoolboxKernelDriver64Bit: Try to make it compatible with both OSX 10.8 and 10.9

This build changes the base SDK to the OSX 10.8 SDK and the deployment
target to OSX 10.8.
This should work on 10.8 and 10.9 and has been successfully tested to
work on 10.9.
Tests for 10.8 pending.
-> Xcode project and PsychtoolboxKernelDriver64Bit.kext.zip updated.
PsychtoolboxKernelDriver64BitLegacy.kext.zip: Restore to September 2013 state for OSX < 10.8 compat.

I can only build new versions of the driver for 10.8 and later - at
best.
Restore the legacy driver for 10.6 and 10.7 to the state of September
2013, the best we can do.
-> 10.6 and 10.7 will be permanently broken wrt. digital display
dithering on AMD pre-HD5000 hardware.
help Psychtoolbox: Update credits and add link to Peter Scarfe's nice tutorial page.
PsychEyelinkDispatchCallback: Fix target drawing for large target dot sizes.

Code unconditionally used ‘DrawDots’, even for dots which might be
beyond the limit of the GPU.
Now use ‘DrawDots’ for dots smaller than 10 pixels diameter, ‘FillOval’
for others.
The limit is hardcoded to a safe 10 pixels setting that should work on
Intel, Nvidia and AMD.
Query of the GPU limit would be possible but a bit more inefficient -
or more work to implement efficiently.
Screen('TextFont'): Allow simultaneous setting of font name and font style.

Do ‘TextFont’ and ‘TextStyle’ in one atomic call. This is needed to
work around broken fonts on OSX in combination with OSX broken font
handling. See forum msg #17286 for the problem.
If a font does not support standard textStyles, it wasn’t possible on
OSX to select it by name, because name selection and style selection
were different calls and each call failed font validation individually,
because it would have had to transition through an invalid state in the
[fontFamilyName, fontStyle] space. Setting both atomically allows to
jump from one valid state to the next valid state and validation
succeeds. This is not needed on Linux or Windows, but now implemented
for compatibility.
On old version of Screen() selection of such a font by fontNumber was
still possible as a workaround.

-> Screen for OSX Matlab & Octave rebuilt and tested.
Screen/Linux: Fix compiler errors introduced by OSX changes.

-> Screen for 64-Bit Octave on Linux rebuilt and tested.