Convert all & operators into && and | ops into || where this is sensible.

First batch, all manually reviewed to be ok.
Replace more & by && and | by || + newline fixes - The complex cases.

These are the ones who needed a bit more care and selective commits.
They contain find() operators, unix shell pipes, real boolean
element-wise or bitops.
Add pathetic & -> && and | -> || converter scripts for reference.
Screen/Linux: Check for open movies at Screen('Close') on Linux as well.

This check was #if def disabled on Linux, probably from the time when
Linux PTB didn't have movie playback support.
Remove M-Lint #ok<OR2> and #ok<AND2> annotation.

No longer needed to suppress mlint warnings, now that operators have
been converted.
Also a few more operator fixes and missing newline at end of file fixes.
Remove M-Lint #ok<OR2,AND2> combi annotations where not needed.
AssertOpenGL: Do not suppress short-circuit operator warnings on Octave.

Now that all M-Files are supposed to be fixed, we no longer suppress
octave
warnings about the problem, so we can spot files we may have missed.
Factor out Matlab Java classpath setup into PsychJavaTrouble(1);

Instead of having multiple copies of the setup code, implement it in
PsychJavaTrouble and execute it if PsychJavaTrouble(1); is called. This
is now used from the PsychtoolboxPostInstallRoutine during regular
installation and update/setup, and from DownloadAdditionsForLinux for
legacy install via outdated v3.0.9 Debian or Ubuntu Psychtoolbox
archives. In case of up to date packages or current NeuroDebian
packages, users should call PsychJavaTrouble(1) once from within Matlab
directly, in additions to PsychLinuxConfiguration.

Update online help text of PsychJavaTrouble to state of PTB 3.0.10+