PsychDefaultSetup: Reset KbName key mappings to non-unified state.

-> So featureLevel 0 works as expected.
KbCheck: Fix online help for octave.
Add demos and PDF for ECVP 2013 tutorial.

The few dedicated demos go into PsychDemos/ECVP2013.
The PDF with the slides goes into PsychDocumentation.
Screen.mex for 32-Bit Octave for Linux on ARM (Nexus-7) rebuilt.

-> Incorporate PsychDefaultSetup() support.
Fixup PsychDefaultSetup(2) setup of normalized colorrange - do still clamp.

PsychDefaultSetup(2) only changes the color range to 0-1, but does not
change clamping state, ie., it doesn't disable framebuffer range
clamping.

Turns out if we indiscriminately disabled clamping, we would run into
problems with old graphics hardware (or less capable software
rasterizers like VirtualBox VM). If the GPU doesn't support
glClampColorARB extension, PTB would choose the shader based
fallback/emulation, which can fail on GPU's with limited or no shader
support, and then scripts would produce color artifacts! While this is
expected behaviour if one explicitely wishes to disable clamping -- one
simply has to use modern hardware in this case, it is an unexpected and
unacceptable failure mode when running on old OpenGL hardware.

Tested on a MS-Windows VM with VirtualBox, where the old approach broke
down due to limitations of VirtualBox's software rasterizer / GPU
emulation. Now works.

PsychImaging updated (code + docs), PsychDefaultSetup help text updated.
All Screen mex files for desktop platforms Linux, OSX, Windows rebuilt.

To provide PsychDefaultSetup(2) support for all but Linux mobile
(Nexus-7), which is a separate commit.
Merge branch 'master' of https://github.com/kleinerm/Psychtoolbox-3
Delete obsolete WinTabMex.mex file for octave on Windows.

-> No support for Octave + Windows, so no point in shipping this anymore.
Move pnet for Matlab on Linux into PsychBasic folder.

This way, the DownloadAdditionsForLinux.m script can fetch the
Matlab mex files on old NeuroDebian/Debian/Ubuntu apt packages.
Adapt helper functions and some demos to PsychDefaultSetup(2);

Make helper functions adaptive to current WhiteIndex().
Make some demos adaptive, others to use PsychDefaultSetup(1);
Fix some bugs along the way…
All our "regular" demos still assume a 0-255 default color range. They
need to get adapted to 0-1 range, or protected via
PsychDefaultSetup(1); in the long term.