Fixes for DEV-50619 Have the low graphics settings be the lowest possible settings for settings with slider bars and DEV-50618 Have Draw Classic Clouds be off for low graphics settings and DEV-50616 Toggling Draw Classic Clouds does not actually prevent them from being drawn if clouds have been drawn once.  Reviewed by qarl

LLObjectBridge::openItem() was concurrency modified.
Applied behavior that was changed in c3220f7f7699 according to
	VWR-13743 FIXED Change Request: Change double click action for inventory wearables
	DEV-33391 FIXED Change Request: Change double click action for inventory wearables

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branch : product-engine

Updated install.xml to point to a version of temporary version LLQtWebKit that skips past SSL/Cert errors so QuickBuy functions can be tested. (Windows only)
Also tweaked the QuickBuy Currency floater so scrollbars do not appear for current Web content

Removed llinfos that was causing excessive spam.

Added TextureDiscardLevel override for specifying texture discard levels.
Aesthetic change to add debug- flag to all avatar debug reporting metrics.

- Enabled 'fit to parent' parameter for accordion

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/440/

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branch : product-engine

EXT-6937 PARTIAL FIXED Enable a possibility to "mute everyone" in case group chat is already in "moderate_mode" state.

Partial fix (until restart moderator's viewer)
* store "moderate_mode" session state
* if session is already in requested state participants un/mute individually.

Known Issue:
"moderate_mode" session state is set to false on startup. Thus if moderator join voice chat with disabled voice it has incorrect state.
In this case when he sends "Mute everyone" request first time it has effect only to himself. Other unmuted participants are not muted.
Next "Mute everyone" request works properly: one request per participant is sent.

Reviewed by Aimee Walton at https://codereview.productengine.com/secondlife/r/423/

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branch : product-engine

Seems, there is a problem somewhere in rendering of LLLAyoutStack children. Last visible panel marked as user_resize=true can not be resized and has no resize cursor.
Because we have no time & resources to investigate this closely a workaround is implemented for bottom tray:
 * set user_resize for layout panel with Speak button which is always visible to user;
 * set user_resize=false to don't have Speak button panel resizable.

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/438/

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branch : product-engine

EXT-7142 FIXED Upload functionality duplicated in the Build menu and Select Linked Parts menu moved up

- LLPanelMainInventory::setUploadCostIfNeeded() - uncommented the line which enables retrieving of the upload cost price using LLGlobalEconomy class.
- Implemented LLUploadCostCalculator event handler in the llviewermenu.cpp (the fact that it should be implemented in this file was discussed with Mike Antipov).
- LLUploadCostCalculator::calculateCost() is implemented only for code readability: it's name is more descriptive than a code snippet placed directly in the constructor (LLPanelMainInventory::setUploadCostIfNeeded() works in similar way: it calculates cost_str only once).
- 'Select Linked Parts' menu was moved below 'Edit Linked Parts'.
- 'Upload' menu was added at the bottom, below 'Options' menu

Reviewed by Mike Antipov at https://codereview.productengine.com/secondlife/r/425/

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branch : product-engine

DEV-33391 FIXED Change Request: Change double click action for inventory wearables

Pulled this from the AvP backlog and implemented it, as it's a pain point from Ben's usability findings.  And people loooove this in 3rd party viewers.
(transplanted from cd0857d027305aec3dbdfe1940a04f7827e3a656)

Reviewed by Mike Antipov and Nyx at https://codereview.productengine.com/secondlife/r/428/

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branch : product-engine

fixed merging logic for blockvalues like rect, uiimage, etc