Added a lot of checking to deal with the fact that the code may encounter a
stub convexDecomposition library. Additionally updated the linux stub to fix the
automated build so our beta testers can finally have a linux build.

Unrelated fix: added upload mesh to the top level upload menu.

Code reviewed by Vir.

step 1 - minor cleanup that allows viewer to build under linux.
Will only run on aditi (crashes on agni), does not download meshes
successfully, and has pretty bad vertex corruption, but it runs!

Code reviewed by Falcon

 -Nyx

Added AgentPositionSnaps data to ViewerStats to measure frequency and scale of interpolation failures.

EXT-7399: FIXED: 2.0.2 with http textures loads textures slower than 1.23.5

--HG--
branch : product-engine

Details:
1 Provided passing necessary is_group parameter to LLPostponedNotification::add<LLPostponedServerObjectNotification> method call;
3 Corrected handling group name in LLPostponedNotification::onCachedNameReceived;
2 Added check on retrieved name from cache name and replacement with fallback value.

reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/743/

--HG--
branch : product-engine

added updating Plus button (Wear Item button) on COF changes (only when Edit Outfit panel is trully visible)

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/742/

--HG--
branch : product-engine

EXT-7639 FIXED (Make shop button open different URLs depending on what is selected in outfit editor)

- Fixed old market place URL to the new one in the settings.xml.
- Implemented the following feature: \"When Add More panel in focus selection inside it should supersede selection in accordions\". To achieve this:
-- LLPanelOutfitEdit::getCOFWearablesSelectionType() function was implemented.
-- LLPanelOutfitEdit::getAddMorePanelSelectionType() function was implemented.
-- LLPanelOutfitEdit::getWearableTypeByItemUUID(const LLUUID& item_uuid) function was implemented.
-- LLPanelOutfitEdit::onShopButtonClicked() was rewritten to use those functions.
- Fixed the problem with shop button and gender: now shop button for male leads to male links.

Reviewed by Vadim Savchuk and Neal Orman at https://codereview.productengine.com/secondlife/r/725/

--HG--
branch : product-engine

--HG--
branch : product-engine

--HG--
branch : product-engine

--HG--
branch : product-engine

EXT-8328 FIXED passed missing parameter (callback) instead of a default one to the LLAppearanceMgr::addCOFItemLink(...)

appearance update callback wasn't passed down to LLAppearanceMgr::addCOFItemLink(...),
so wearables list was updated before receiving server response regarding creating of the COF item link

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/741/

--HG--
branch : product-engine

Reviewed by Neal Orman at https://codereview.productengine.com/secondlife/r/680/.

--HG--
branch : product-engine

Corrected question string in xml.

Trivial fix- no review.

--HG--
branch : product-engine

Reviewed by Mike Antipov at https://codereview.productengine.com/secondlife/r/738/

--HG--
branch : product-engine

Made LLPipeline::generateWaterReflection() not try to call LLVOAvatarSelf::updateAttachmentVisibility() if isAgentAvatarValid() returns false.

Reviewed by Nyx at http://codereview.lindenlab.com/2585007