This is already done for TeamCity builds in build.sh, but since we don't yet
have 64-bit Xcode 8 Mac Havok working in the viewer, make plain developer
autobuild builds work also.

Aside from crazy indentation, much of Havok.cmake is redundant testing of
DEBUG_PREBUILT and conditional MESSAGE(STATUS ...) output, not to mention
repeating stanzas for each of debug_dir, release_dir and relwithdebinfo_dir.

Use local functions and foreach() to try to manage redundancy so the details
of what it's actually trying to do don't get lost in the noise.

converting to logging so that stdout from its command can be captured
cleanly
Make the default be to not print anything

At some point the INTEGRATION_TEST_llurlentry build changed so that the
library(ies) we attempted to stub out got linked in anyway, so that instead of
simplifying the test, the stubs broke it with "duplicate symbol" errors.
Commenting out the stubs permits the test program to succeed.

Instead, since gSavedSettings is an LLControlGroup and LLControlGroup derives
from LLInstanceTracker, just look up the LLControlGroup with canonical name.

As of now, this fork requires Xcode 8, which introduces support for the -quiet
switch.

First batch of changes to add LibVLC media plugin to macOS viewer. Plugin fails to start because of an as-yet undiagnosed issue with VLC plugin files related to their extyended attributes

and re-enable breakpad symbol generation.

The CMake directive that passes VIEWER_CHANNEL to the C++ compiler as
LL_VIEWER_CHANNEL was enclosing the VIEWER_CHANNEL value in double quotes. At
this point in history, those double quotes literally become part of the
LL_VIEWER_CHANNEL value, causing the viewer to construct a bad Viewer Version
Manager query containing those double quotes. Removing them fixes the query.

from autobuild.xml's darwin64 Release and ReleaseOS build (xcodebuild)
command.

-D passed to xcodebuild does NOT set CMake variables. These switches, in this
 place, have never worked as intended.

When LL_BUILD is not in the environment at autobuild configure time, important
macros such as LL_WINDOWS aren't set. That means that platform-dependent
macros such as LL_TYPEOF() aren't defined, which can produce obscure errors
like this:

indra\llcommon\llunittype.h(51): error C2226: syntax error :
unexpected type 'S' (packages\llphysicsextensions\stub\LLPhysicsExtensionsStubImpl.cpp)
10>          indra\llcommon\llunittype.h(52) :
see reference to class template instantiation 'LLResultTypeAdd<S,T>' being compiled

Make the CMake logic fail with a more readily-understood error in that case.