* #926 WIP - HDRI import prototype v0

* #926 WIP -- add OpenEXR to autobuild.xml

* #926 WIP -- Add OpenEXR cmake

* #926 WIP -- Attempt at using OpenEXR autobuild package and don't hard code .exr file to load

* #926 Unmangle autobuild.xml and get dll's in the right place (thanks, Caladbolg!)

* implement mac shared libs plumbing for OpenEXR for secondlife/viewer#926

* Fix Xcode/clang compile error regarding new[]/delete[] mismatch

* #926 HDRI Preview finishing touches.

- Full ACES when HDRI is enabled
- Fix for probes getting stuck paused
- Add exposure and rotation controls

---------

Co-authored-by: Brad Linden <brad@lindenlab.com>

#681 Mirrors quality pass 1.

Shift-dropping textures can fail if one of 'early' faces has nomod
material

PBR Terrain UI second pass

Issue #54 LLRender::init crash and SL-17896

Under debug LL_ERRS will show a message as well, but release won't show
anything and will quit silently so show a notification when applicable.

secondlife/viewer#712: Use checkbox to make it more obvious that only one set of terrain assets is preserved. Clean up enums.

instead of the branch that got pulled.

(cherry picked from commit b42e01d7)

instead of on the current tag 7.1.2-release.

(cherry picked from commit 27b298d8)

This should (!) allow us to generate full release notes relative to the
previous viewer release, instead of letting action-gh-release guess
incorrectly.

Also try again to add to the release page a back-link to the specific build.

(cherry picked from commit 88ebb92f)

(cherry picked from commit 4edd78f2)

Using github.ref as action-gh-release's target_commitish produces:

 GitHub release failed with status: 422
[{"resource":"Release","code":"invalid","field":"target_commitish"}]

(cherry picked from commit c6a6db84)

Also try to cross-reference release page and build page.

(cherry picked from commit a908b4cf)

Put whatever release notes we retrieve into the generated release page.

(cherry picked from commit ff543b74)

Now that which_branch.py has moved to viewer-build-util, so has the PyGithub
dependency.

(cherry picked from commit dd0ec112)

which_branch.py has moved to viewer-build-util as a reusable action.

(cherry picked from commit 09f66828)

(cherry picked from commit 2c5066f1)
(cherry picked from commit ff1741ce)

in viewer's autobuild-package.xml.

Ensure that AUTOBUILD_VCS_BRANCH is set before the build.

(cherry picked from commit b782ab73)
(cherry picked from commit 6e8d4f48)

The release job has been dependent on sign-and-package-windows and
sign-and-package-mac, each of which depends on build. But that indirect
dependency doesn't convey access to ${{ needs.build.outputs.xxx }}. Add the
build job to direct dependencies so release can access its outputs.

(cherry picked from commit 819604d2)

(cherry picked from commit 6654ad14)

(cherry picked from commit 59eeaed1)

For a tag build that generates a release page, try to deduce the git branch to
which the tag we're building corresponds and add that to release notes.

(cherry picked from commit 9e99bb04)

(cherry picked from commit f7166222)

following promotion of secondlife/viewer #673

secondlife/viewer#712: More intuitive selection of PBR vs texture terrain, and update dropdown to match