Merge pull request #24 from Psychtoolbox-3/master

PTB BETA RELEASE "Rainbows, Droids & Compute Hippies!" SP3

* Make java path setup in postinstall routine more robust against users doing weird things.
SetStereoBlueLineSyncParameters(): Also work in stereomode 11, not only 1.
IsGUI: Adapt Octave code to 3.7.3+ GUI prototype.

Octave now has a builtin function isguirunning() which provides us
with the required info, whereas the old detection heuristic failed
on Ubuntu 13.04 with v3.7.3+
PsychtoolboxKernelDriver.m: Clarify meaning of PathToPsychtoolbox in help.

For people which read too literally.
Screen/OSX: Clarify CoreVideo timestamping message.

Reformulate the message again to convey that the deficient CoreVideo
timestamping would be only used as fallback if beamposition timestamping
would be unavailable or malfunctioning.

Only output the suggestion to install the PsychtoolboxKernelDriver
if the driver isn't already available and connected. Otherwise people
are confused.

Rebuild and testing on OSX pending.
Screen: Allow to create hidden/invisible onscreen windows.

If Screen('Preference','WindowShieldingLevel', -1); is set
before/during call to Screen('Openwindow') for a non-fullscreen
window with kPsychGUIWindow 'specialflags' set, then create
the onscreen window as usual, but do not show/map it, so it
stays invisible on the display.

This is useful if one wants to (ab)use Psychtoolbox as an
offscreen renderer. One can create such an onscreen window,
then an associated 'Offscreenwindow' and then render and
'GetImage' from that offscreen window. The offscreen window
can have arbitrary size and resolution (within the hardware
and vram memory limits of the gpu of course).

One should probably disable sync tests etc. as in
PsychDebugWindowConfiguration() to avoid sync errors
or lots of warning clutter for such a window.

Screen for 64-Bit Octave on Linux rebuilt and tested.
MaskImageIn(), MaskImageOut() - Make it actually work.

This was untested and entirely broken since day 1!
Hopefully fixes issue #109
Improve geometric BVL display calibration routines.

Wait for keyboard input on all connected keyboards.
Add support to select stereoMode for display calibration,
e.g., mode 4 for dual-display co-calibration.

Improvements mostly contributed by Bas Rokers.
PRxxxinit: Don't flush serial port buffers on write.

Add DontFlushOnWrite=1 option to serial port open for the PRxxx
photometer toolboxes. At least on PR-Photometer hangs in the
flush on Linux and we don't need flushing for those functions
anyway, so just avoid it for all of them on all os'es.

Should fix problem reported in forum message #15652.
All Screen mex files rebuilt, except for 32-Bit Matlab on OSX.

-> 32-Bit OSX is deprecated, so skip it.
-> This integrates the less scaring CVDisplayLink timestamping warning
message for OSX 10.7+, which also doesn't ask for installation of the
kernel driver if it is already installed and active.
-> It also enables Screen('preference','windowshieldinglevel', -1) for
all operating systems to allow to open completely hidden/invisible
onscreen windows for offscreen/offline rendering tasks.
DownloadPsychtoolbox: Move /opt/subversion/bin first as search path for svn.

To match a similar change of David in GetSubversionPath().
Merge pull request #118 from kleinerm/master

PTB BETA RELEASE "Rainbows, Droids & Compute Hippies!" SP4