SL-12902 Fix for doing the technically correct but compatibility wrong thing WRT light color values.

Longtime fans will remember that the "dcoroutine" library is a Google Summer
of Code project by Giovanni P. Deretta. He originally called it
"Boost.Coroutine," and we originally added it to our 3p-boost autobuild
package as such. But when the official Boost.Coroutine library came along
(with a very different API), and we still needed the API of the GSoC project,
we renamed the unofficial one "dcoroutine" to allow coexistence.

The "dcoroutine" library had an internal low-level API more or less analogous
to Boost.Context. We later introduced an implementation of that internal API
based on Boost.Context, a step towards eliminating the GSoC code in favor of
official, supported Boost code.

However, recent versions of Boost.Context no longer support the API on which
we built the shim for "dcoroutine." We started down the path of reimplementing
that shim using the current Boost.Context API -- then realized that it's time
to bite the bullet and replace the "dcoroutine" API with the Boost.Fiber API,
which we've been itching to do for literally years now.

Naturally, most of the heavy lifting is in llcoros.{h,cpp} and
lleventcoro.{h,cpp} -- which is good: the LLCoros layer abstracts away most of
the differences between "dcoroutine" and Boost.Fiber.

The one feature Boost.Fiber does not provide is the ability to forcibly
terminate some other fiber. Accordingly, disable LLCoros::kill() and
LLCoprocedureManager::shutdown(). The only known shutdown() call was in
LLCoprocedurePool's destructor.

We also took the opportunity to remove postAndSuspend2() and its associated
machinery: FutureListener2, LLErrorEvent, errorException(), errorLog(),
LLCoroEventPumps. All that dual-LLEventPump stuff was introduced at a time
when the Responder pattern was king, and we assumed we'd want to listen on one
LLEventPump with the success handler and on another with the error handler. We
have never actually used that in practice. Remove associated tests, of course.

There is one other semantic difference that necessitates patching a number of
tests: with "dcoroutine," fulfilling a future IMMEDIATELY resumes the waiting
coroutine. With Boost.Fiber, fulfilling a future merely marks the fiber as
ready to resume next time the scheduler gets around to it. To observe the test
side effects, we've inserted a number of llcoro::suspend() calls -- also in
the main loop.

For a long time we retained a single unit test exercising the raw "dcoroutine"
API. Remove that.

Eliminate llcoro_get_id.{h,cpp}, which provided llcoro::get_id(), which was a
hack to emulate fiber-local variables. Since Boost.Fiber has an actual API for
that, remove the hack.

In fact, use (new alias) LLCoros::local_ptr for LLSingleton's dependency
tracking in place of llcoro::get_id().

In CMake land, replace BOOST_COROUTINE_LIBRARY with BOOST_FIBER_LIBRARY. We
don't actually use the Boost.Coroutine for anything (though there exist
plausible use cases).

Provide method of storing joint indices sep from weight data for faster runtime processing.

Will wait for a response from @graham_linden regarding moving the sRGB conversion functions in llmath.h to llrender.

Make sure lights are in the correct color space.
Bonus: cache the sRGB color in setLightColor on point and spot lights.  Frees up a pow and some multiplies on the CPU every frame.

Make shader loading debug logging of uniforms use ShaderUniform to make supression simpler.

Fix sync of material rotation and offset values when using aligned planar faces.

Make it possible to set a specific TE's normal/spec offset/rotation values.

Eliminate redundant conversions in LLSD -> struct handler.

MAINT-8676  modify XUI to allow negative offsets again and fix up material handling of normal/specular offsets

MAINT-7847 The presence of certain Avatars stops local specular textures from "sticking". Yes really.

FIXED. Allows set material explicitly to material manager.

MAINT-8208 [Mac] Viewer crashes when uploading certain mesh model after enabling "Include skin weight"

MAINT-8208 [Mac] Viewer crashes when uploading certain mesh model after enabling "Include skin weight"

MAINT-6645 - Improvement - Agents that render as jelly dolls should have their attachments render at 0 LoD to prevent loading higher LoD complexity in memory thus deterring crashes.
Stability improve. (viewer x64)

SL-694 - Added extra param field for flags related to extended mesh functionality. Currently this is just one bit to flag an object as able to animate

MAINT-6645 - Improvement - Agents that render as jelly dolls should have their attachments render at 0 LoD to prevent loading higher LoD complexity in memory thus deterring crashes.
Comments:
- Fix based on "RenderAutoMuteByteLimit" setting.
- File indra/llxml/llcontrol.h - add all signals to 0 group.
  It garanty that handlers (in indra/newview/llviewercontrol.cpp) will be called last.