Fix XUI parser warnings:

* LLFloaterMarketplace::postBuild calls parent method which already tries to find the webbrowser control with a different name and adds itself as observer
* Incorrect attribute name "tooltip" in panel_preferences_move.xml

indra/newview/llfloatermarketplace.cpp

@@ -46,9 +46,9 @@ void LLFloaterMarketplace::onClose(bool app_quitting)
 
 bool LLFloaterMarketplace::postBuild()
 {
-    LLFloaterWebContent::postBuild();
-    mWebBrowser = getChild<LLMediaCtrl>("marketplace_contents");
-    mWebBrowser->addObserver(this);
+    if (!LLFloaterWebContent::postBuild())
+        return false;
+
     mWebBrowser->setErrorPageURL(gSavedSettings.getString("GenericErrorPageURL"));
     std::string url = gSavedSettings.getString("MarketplaceURL");
     mWebBrowser->navigateTo(url, HTTP_CONTENT_TEXT_HTML);

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

@@ -169,7 +169,7 @@
         follows="all"
         layout="topleft"
         left="0"
-        name="marketplace_contents"
+        name="webbrowser"
         top="0"/>
     </layout_panel>
     <layout_panel name="status_bar" 

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

@@ -214,7 +214,7 @@
    left_pad="10"
    top_delta="-6"
    name="mouse_warp_combo"
-   tooltip="Controls warping of the mouse to the center of the screen during alt-zoom and mouse look."
+   tool_tip="Controls warping of the mouse to the center of the screen during alt-zoom and mouse look."
    width="200">
     <combo_box.item
      label="Automatic"