EXT-2823 Find window: change default open location to the top-left of screen

EXT-2921   	 [BSI] Default location for Screenshot Floater hides expanded options off screen
reviewed by James

indra/llui/llview.cpp

@@ -2533,6 +2533,7 @@ void LLView::setupParams(LLView::Params& p, LLView* parent)
 			else
 			{
 				p.rect.left = p.rect.left + parent_rect.getWidth()/2 - p.rect.width/2;
+				p.rect.right.setProvided(false); // recalculate the right
 			}
 		}
 		else
@@ -2553,6 +2554,7 @@ void LLView::setupParams(LLView::Params& p, LLView* parent)
 			else
 			{
 				p.rect.bottom = p.rect.bottom + parent_rect.getHeight()/2 - p.rect.height/2;
+				p.rect.top.setProvided(false); // recalculate the top
 			}
 		}
 		else

indra/newview/skins/default/xui/en/widgets/floater.xml

@@ -8,6 +8,8 @@
          background_visible="true"
          background_opaque="false"
          header_height="25"
+         top="0"
+         left="0" 
   close_image="Icon_Close_Foreground"
   restore_image="Icon_Restore_Foreground"
   minimize_image="Icon_Minimize_Foreground"