MAINT-4106: Correcting crash on exit behavior during normal shutdown.  With the more comprehensive texture cleanup going on, this code was causing an crash on exit when gAgentAvatarp was null.  Adding a check for null before proceeding.

MAINT-4077: Refactoring to add copy constructors to the LLVisualParam class and all of its derived descendants in order to clarify ownership of memory pointers.

MAINT-4009: Final pass refactoring to eliminate memory allocation related to error reporting that is not properly cleaned up.

MAINT-4009: First pass refactoring to eliminate memory related to error reporting that is not properly cleaned up.

MAINT-4009: Patching a leak of LLVisualParam derived objects that were being leaked because the LLWearable class was not destroying itself properly.

MAINT-4009: Patching the final leak of LLViewerFetchedTexture objects occurring because the LLWearable class was not properly destroying itself.

MAINT-4009: Patching a minor leak for when the status text box for the folder view has not been reparented.

MAINT-4009: Patching a leak of keyframed motions that had been deprecated but were never properly destroyed.

MAINT-4009: Improved patching of a memory leak for when menu items are created before the viewer window initialization has created the menu holder.  See also changeset bc0743639926a84b38b4907d252eff1cc0498c7d.

MAINT-3981 FIXED [SECURITY] Notecard being passed around that crashes any V3 based viewer when opened.
Correct fix after testing.

MAINT-4009: Ensuring that the spare browser media source is cleaned up with the LLViewerMedia class.

MAINT-4009: Patching a small memory leak for when menu items were being created before the viewer window initialization had created the menu holder.  Also, added llasserts in other cases when referencing the menu holder to ensure the holder is non-null.

MAINT-4009: Patching the memory leak occurring from the info icons that appear when hovering over a chat history item.

MAINT-4009: Patching the memory leak occurring in the scenario where avatar icon was being created, but the tab container did not have a button to accept the gieven icon.

MAINT-4009: Patching the memory leak occurring in the scenario where toast panels were being created, but the screen channel were deciding not to display the given toasts.

MAINT-4009: Patching the LLTabContainer that was leaking some child views and their associated llimage allocations.

MAINT-4009: Patching another memory leak in LLBadgeOwner that indirectly was also causing leaks in llimage.

MAINT-4009: Ensuring that the pick mask for the LLImageGL is always properly freed during its cleanup method.

MAINT-4009: Converting the Globals class within llerror to be derived from LLSingleton so that it may be cleaned up properly on app exit.

MAINT-4009: Cleaning up some statically allocated memory in a LLVolumeGeometryManager method that was never freed.