[MAINT 8081] - show/hide avatar base mesh regions if avatar joint attachments are using server bakes. pass the magic ids correctly across ui and texture entry.

[MAINT-8081] - bakes on mesh. 1st pass. changed texture panel to select bakes on objects. handle magic bake ids in LLViewerObject.

Originally a fix for MAINT-4773. This was causing a number of issues since
changes made in this code were pushing null textures into server and viewer
should not modify 'content' at server of own violition.

- Fix member init order
- Use override specifier everywhere
- Add required typename and template keywords
- Replace smart pointer ctors with make functions where available
- Replace 0 and NULL in pointer context with nullptr

--HG--
branch : RLVa

MAINT-6317 [QuickGraphics-RC] Some rigged mesh attachments render fully on jellybaby avatars when ALM is enabled
FIXED
- remove global identifier for the black texture
- add black texture 2x2x3 localy on apllication startup
- add special flag to LLViewerFetchedTexture for protect from removing

The problem was that class-static LLUrlEntryParcel::sRegionHost was being
initialized by copying class-static LLHost::invalid. Naturally, these two
statics are initialized in different source files. Since C++ makes no promises
about the relative order in which objects in different object files are
initialized, it seems we hit a case in which we were trying to initialize
sRegionHost by copying a completely uninitialized LLHost::invalid.
In general we might attempt to address such cross-translation-unit issues by
introducing an LLSingleton. But in this particular case, the punch line is
that LLHost::invalid is explicitly constructed identically to a
default-constructed LLHost! In other words, LLHost::invalid provides nothing
we couldn't get from LLHost(). All it gives us is an opportunity for glitches
such as the above.
Remove LLHost::invalid and all references, replacing with LLHost().

This bug fix related also to MAINT-4092. In 4092 sometimes when we
don't have information about the texture during the setup the materail
(LLVOVolume::setTEMaterialParams()), we should substitute the material with
disabled "diffuse alpha mode" (for detail in cases see MAINT-4092 JIRA ticket
comment).
This bug fix cover the case when after the loading texture we have all
information about alpha mode, and in this case we should restore diffuse
alpha mode if need.

In short: now we always believe that information about the material is valid
(LLVOVolume::setTEMaterialParams()).
Of course before setup it we check information about texture (if it possible)
, if texture is not exist in database or not 32 bit depth (for diffuse) we
made changes.
But in all other cases (if we can't receive information about texture)
we remeber this case in mWaitingTextureInfo multimap.
When information about texture will be available we get it in:
LLVOVolume::notify AboutCreatingTexture()
or
Volume::notifyAboutMissingAsset()
and again, we recheck it and if need change (substitute)
the material parameters.
I suppose that this solution is better than was before.

If this patch will be accepted
, I think that MAINT-4092 should be rechecked again.

This bug fix related also to MAINT-4092. In 4092 sometimes when we
don't have information about the texture during the setup the materail
(LLVOVolume::setTEMaterialParams()), we should substitute the material with
disabled "diffuse alpha mode" (for detail in cases see MAINT-4092 JIRA ticket
comment).
This bug fix cover the case when after the loading texture we have all
information about alpha mode, and in this case we should restore diffuse
alpha mode if need.

In short: now we always believe that information about the material is valid
(LLVOVolume::setTEMaterialParams()).
Of course before setup it we check information about texture (if it possible)
, if texture is not exist in database or not 32 bit depth (for diffuse) we
made changes.
But in all other cases (if we can't receive information about texture)
we remeber this case in mWaitingTextureInfo multimap.
When information about texture will be available we get it in:
LLVOVolume::notify AboutCreatingTexture()
or
Volume::notifyAboutMissingAsset()
and again, we recheck it and if need change (substitute)
the material parameters.
I suppose that this solution is better than was before.

If this patch will be accepted
, I think that MAINT-4092 should be rechecked again.

brought back llfloaterlagmeter from the dead, and ported to lltrace

Limit should be however much vram is installed, but underneath the hood, fudge
how much memory is used for textures to avoid swapping.

Also, catch exceptions when attempting to build a GL context on windows and
display an error dialog instead of crashing.

continued conversion to units system
made units perform type promotion correctly and preserve type in arithmetic
e.g. can now do LLVector3 in units
added typedefs for remaining common unit types, including implicits