PTB BETA RELEASE "Blue skies and empty brains" - SP2

* Fix download failure for 3.0.10 in DownloadPsychtoolbox.m on 32-Bit OSX.
* Fix mex file load errors on 64-Bit Octave for OSX with Fink package manager and other versions.
* New function Eyelink('SetAddress') for setting tracker computer target IP address.
* Enable raw sample data access for Eyelink on Linux.
* Update PsychVideoSwitcher help.
* Update some other help texts, e.g., DisplayOutputMappings.
* Add new text rendering mode 0 on OSX for new-style ATSU rendering of problematic exotic fonts.
* Add GstX264Enc video encoding profile for fast camerabin2 video recording with GStreamer SDK.
* Some new demos and improvements from David Brainard in area of color calibration or simulation?
* New function GetGITPath from Ben Heasley.