following promotion of DRTVWR-540

According to davep, the intent of Debug GL is to crash and in this it's doing it's job, but the rest of the fix that makes the state not persist is a good solution.

RenderDebugGL was avaliable from develop menu, but since it was persistent, caused slowdowns and crashes it could result in users crashing or lagging without knowing the cause. To resolve the issue it was made to last for a single session.

(cherry picked from commit 7f0259f0e767969d260514e9ea810cbde7f1d24c)

The whole methode is questionable in doing nothing and it seems there was a deliberate change
that made sure it does nothing. I am not sure what this method really is supposed to do, thus I did opt
for the most basic version of "do nothing" like it was before.

(cherry picked from commit 1c1a93e42e209e959f09ec46ca414a8936f4ac20)

(cherry picked from commit 5c6228e56a688a98606ce28077d6089adc833873)

More DRTVWR-550 Teamcity build fix. another piece of python2 syntax leftover in an error handling block

Nicky Dasmijn's contribution for zlib-ng Linux builds