[Issue 662] Make the Region/Estate's Covenant panel's text editor take up as much space as the LL Viewer's.
[Issue 662] STORM-1265: Combine Terrain and Ground Textures tabs in Region/Estate floater
[Issue 662] In preparation for Environment panel, sync panel_region_estate.xml
[Issue 662] Switch to using LLEstateInfoModel

Applies part of STORM-1506 patch from https://codereview.secondlife.com/r/397/
Removes old WindLight parts from code.
[Issue 662] Add Environment tab to Region/Estate Floater.
[Issue 662] Allow Version text on Region/Estate region tab to be as long as it needs to be
[Issue 662] Plug in LLPanelEstateInfo::updateEstate* functions
[Issue 662] The text replacing certain heading texts to be as wide as it needs to be