MAINT-6775 ParserWarning spam in viewer log

indra/newview/skins/default/xui/en/floater_avatar.xml

 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <floater
  positioning="cascading"
- ignore_ui_scale="false"
  legacy_header_height="225"
  can_minimize="true"
  can_close="true"

indra/newview/skins/default/xui/en/floater_camera.xml

@@ -49,7 +49,6 @@
          layout="topleft"
          left="8"
          name="preset_views_list"
-         opaque="true"
          top="24"
          width="212"
          visible="false">
@@ -107,7 +106,6 @@
           layout="topleft"
           left="8"
           name="camera_modes_list"
-          opaque="true"
           top="24"
           width="212"
           visible="false">

indra/newview/skins/default/xui/en/floater_destinations.xml

 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <floater
  positioning="cascading"	
- ignore_ui_scale="false"
  legacy_header_height="225"
  can_minimize="true"
  can_close="true"
- user_resize="true"
  can_resize="true"
  min_height="230"
  min_width="350"

indra/newview/skins/default/xui/en/floater_edit_hover_height.xml

 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <floater
  positioning="cascading"
- ignore_ui_scale="false"
  legacy_header_height="225"
  can_minimize="true"
  can_close="true"

indra/newview/skins/default/xui/en/floater_im_container.xml

@@ -121,7 +121,6 @@
              follows="all"
              layout="topleft"
              name="conversations_list_panel"
-             opaque="true"
              top_pad="0"
              left="5"
              right="-1"/>
@@ -144,7 +143,6 @@
                  follows="all"
                  layout="topleft"
                  name="stub_panel"
-                 opaque="true"
                  top_pad="0"
                  left="0"
                  right="-1">

indra/newview/skins/default/xui/en/panel_notification.xml

 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <panel
   background_opaque="false"
-      border_visible="false"
+  border_visible="false"
   background_visible="true"
   bg_alpha_color="PanelNotificationBackground"
   bg_opaque_color="PanelNotificationBackground"
@@ -10,18 +10,17 @@
   left="0"
   name="notification_panel"
   chrome="true"
-  show_title="false"
   top="0"
-  	height="140"
+  height="140"
   translate="false"
   width="305">
   <!-- THIS PANEL CONTROLS TOAST HEIGHT? -->
   <panel
-      border_visible="false"
- bevel_style="none"
+    border_visible="false"
+    bevel_style="none"
     background_visible="true"
-  bg_alpha_color="ToastBackground"
-  bg_opaque_color="ToastBackground"
+    bg_alpha_color="ToastBackground"
+    bg_opaque_color="ToastBackground"
     follows="left|right|top"
     height="100"
     label="info_panel"

indra/newview/skins/default/xui/en/panel_outfit_gallery.xml

@@ -34,12 +34,9 @@
     Searching...
   </text> 
   <scroll_container
-   border="true"
-   bevel_style="none"
    follows="all"
    height="400"
    width="312"
-   min_width="312"
    layout="topleft"
    left="4"
    top="0"

indra/newview/skins/default/xui/en/sidepanel_inventory.xml

@@ -59,7 +59,6 @@
                  name="inbox_layout_panel"
                  visible="false"
                  min_dim="35"
-                 max_dim="235"
                  expanded_min_dim="90"
                  height="235">
                  <panel