Nicky Dasmijn's contribution for zlib-ng Linux builds

Remove all boost, fix calling functions on nullptrs, initialize vars

Approved-by: Maxim Nikolenko
Approved-by: Nat Linden
Approved-by: Andrey Lihatskiy

# Conflicts:
#	autobuild.xml

of it.

really bad idea ...

following promotion of DRTVWR-557

Since python 3.3 sys.platform for Linux will always be 'linux'. See https://bugs.python.org/issue12326 - fix by NickyD

There is a few peculiar differences in default member initializationn namely:
gamma > 1.0f; sun_norm > 0.0f, 1.0f, 0.0f, 1.0f; cloud_shadow > 1.0f; dome_radius > 1.0f; dome_offset > 1.0f
Which probably made the original memset produce the wrong result anyway as it differs from the value the
LLVOSky set (the default ctor of AtmosphericsVars) vs what the memset would produce in case of a force update (all 0s).

Update CMakeLists of doxygen project to require at least cmake 3.8.0 (same version as viewer) to get rid of deprecation warning.

This picks up the change to 32-bit Windows viewer-manager.

# Conflicts:
#	autobuild.xml
#	indra/newview/llappviewer.cpp
#	indra/newview/viewer_manifest.py

Fix template verifier erroneously failing checksum check

Approved-by: Nat Linden
Approved-by: Signal Linden
Approved-by: Andrey Lihatskiy

(cherry picked from commit 5fcb811a)

'from __future__ import print_function' not only makes the print() function
available, it also makes the Python 2 print statement invalid syntax. Until we
merge with the Python 3 branch (soon!), don't import print_function: instead
revert to 'print >> sys.stderr' statements.

Instead we have a new bundled executable SLVersionChecker, so that must be
signed instead of _greenlet.so.

On Mac, execute the packaged SLVersionChecker directly rather than invoking
system Python on our manually-bundled scripts.

1. When SL window closes it doesn't mean that process died so gave it a bit more time to terminate
2. Added a retry logic in case first run happened too early for some reason
3. Replaced ok/cancel on locked file with abort/retry/ignorei