SL-17451 Fix for erroneous attempt to apply vertex color alpha to texture before alpha masking (we don't actually support this and the vertex color alpha is sometimes zero when you think it ought not be).

If there is no vcruntime140_1 in the build system, it is likely that file is not required for the viewer to run.

access violation, 'this' was null

# Conflicts:
#	indra/newview/llappviewer.h

following promotion of DRTVWR-550

- Do not try initializing shaders if requirements are not met or if window does not exist
- Warn user before closing window. Situation is unexpected, there is chance of more issues, like a freeze or a crash on close()
- mHasMultitexture is a solid requirement, if it is not present, we won't be able to run

SL-17239 Override face bounding box with avatar bounding box for rigged meshes when calculating virtual size.

LLWord should persist till the end due to wide usage.

Pausing clouds should not pause water

# Conflicts:
#	indra/llcommon/llsdutil.cpp
#	indra/newview/VIEWER_VERSION.txt
#	indra/newview/lldrawpoolalpha.cpp
#	indra/newview/lldrawpoolwater.cpp

following promotion of DRTVWR-540

SL-17194 Impostor quality pass 2 (and fix for fully transparent rigged attachments rendering to depth buffer)