First build of Screen() on Nexus7

Add a new temporary mode 1000 to linuxmakeitoctave3.
This builds Screen.mex for 32-Bit Octave for the 32-Bit
Ubuntu 13.04 prototype installed on the Tegra-3 based
Google Nexus-7 tablet. Waffle library must be installed
and is dynamically linked. All psychtoolbox-3 build deps
from the Ubuntu Multiverse repo are needed.

Currently only Screen.mex was built, as all the other
mex files are already provided by Debian/Ubuntu and
seem to work reasonably well, although they belong to
the outdated PTB 3.0.9. The self-built Screen and the
mex files from Ubuntu are included in a new folder
Psychtoolbox/PsychBasic/Octave3LinuxFilesARM/

This is all temporary duct-tape for now.
Screen doesn't work yet. It manages to initialize
Waffle + X11/EGL backend + OpenGL-ES1 with some hand-
holding, but fails in glGetString() for not yet known
reasons. This is a backup commit.