SH-412 -- fix the way that redraws happen to eliminate flickering on resize -- patch from davep and seraph, I'm just applying it.

STORM-535 FIXED PLEASE allow adjustable transparency of "Nearby Chat" window, Chat History and Chat "Toasts" in Viewer 2.0!

- Added to the settings.xml values of transparency for active and inactive floaters

- Added three members to the LLFloater. These members store current transparency of floater, transparency of active and inactive floaters.

- Added callbacks that update transparency value of active and inactive floater. Also in these callbacks value of current floater transparency updated.

- In panel preferences advanced added two spinners: transparency of active floaters and inactive ones. See screenshot.

fixed logic so that ignore consistently means *don't show* the notification
the ignore settings still store "show the notification if true" values

reverted to old sense where ignore setting of notifications has meaning true=show false=ignore
reviewed by Callum

STORM-284 FIXED Disabled "+" sign when user tries to drop a landmark to Favorites bar from any location besides My Inventory or Library.

* Bump CacheNumberOfRegionsForObjects up to 20k in the default settings.
* Make LLVOCache *actually* use this setting, with no upper bound.

Reviewed with Kelly.