This commits a slightly modified patch from my patch tracker item #3104630
"OSYSTEM: Add logging API as proposed by Max on -devel".
I was not able to test compilation on Android and SamsungTV, since there is no
toolchain for those on buildbot (or I was too blind to find them).
svn-id: r54339
This appears to work around a blank screen bug Nexus1. I never
tracked it down, but as far as I can tell it is triggered by multiple
overlapping updates before flushing the texture to screen. This
condition only happens in the overlay atm so an extra redraw isn't the
end of the world.
(Also remove an unused _full_screen_dirty property)
svn-id: r53801
