Merge pull request #22 from Psychtoolbox-3/master

Resync with current master of official Psychtoolbox-3 repo.
Post release of "Rainbows, Droids & Compute Hippies".
PsychGPUControl: Add use of 64-Bit ATIRadeonperf_Linux64 exe on 64-Bit Linux.

We have a dedicated 64-Bit executable, so we do not require installation of
32-Bit compatibility libraries on 64-Bit Linux systems just for our little
exe here, as that would be wasteful.

Add 64-Bit compiled ATIRadeonperf_Linux64 executable.

Fixes Issue #21
PR-Photometer toolboxes: Add 'Lenient' option to serial port open.

Add the 'Lenient' keyword so IOPort accepts some non-critical
failures during serial-port connection open, e.g., the failure
to enable low-latency mode on a serial link, without aborting
with error.

Some serial port drivers don't support such settings, so failure
would be guaranteed, e.g., the PR-XXX photometer setup on Linux.

Should fix issue from Psychtoolbox forum message #15535.

Modified PR650/655/670/705init.m
Merge pull request #112 from kleinerm/master

PTB BETA RELEASE "Rainbows, Droids & Compute Hippies!" SP1

* Fix PRxxx support on Linux.
* Fix missing 64-Bit Radeoncontrol exe on Linux.