Merge changes from origin/7.1

0d4080b ContainerEventProvider returns style names from container. Fixes #10718
6e91bdf Add test for TransactionalPropertyWrapper memory leaks
f0aaf89 Fixed resetting of ComboBox if focused and new items allowed (#13413).
e033fcd Always initialize WebBrowser for new sessions (#13571)
168de1f Revert "Drag image for text-area should contain text of text-area (#13557)"
35e2a34 Fix FieldGroup and TransactionalPropertyWrapper memory leaks (#13438)
7e5d44d Introduce a drag threshold for Drag and Drop (#13381)
f227f0c Drag image for text-area should contain text of text-area (#13557).

Change-Id: Idb01471f8ab0c7118fa884c364e6bc200d13948a

diff --cc client/src/com/vaadin/client/ui/dd/VDragAndDropManager.java
Simple merge

diff --cc server/src/com/vaadin/data/fieldgroup/FieldGroup.java
Simple merge

diff --cc server/src/com/vaadin/server/BootstrapHandler.java
index bfdbea3086e9c308be542471f59f9c8f4dd02a6b,60b4459d2ae2899e8258f69163d3205508823a59..069cd61253b295178c0db266efb8e580b12cf98b
--- 1/server/src/com/vaadin/server/BootstrapHandler.java
--- 2/server/src/com/vaadin/server/BootstrapHandler.java
+++ b/server/src/com/vaadin/server/BootstrapHandler.java
@@@ -155,11 -148,13 +155,7 @@@ public abstract class BootstrapHandler 
      @Override
      public boolean synchronizedHandleRequest(VaadinSession session,
              VaadinRequest request, VaadinResponse response) throws IOException {
 -        if (ServletPortletHelper.isAppRequest(request)) {
 -            // We do not want to handle /APP requests here, instead let it fall
 -            // through and produce a 404
 -            return false;
 -        }
 -
          try {
-             // Update WebBrowser here only to make WebBrowser information
-             // available in init for LegacyApplications
-             session.getBrowser().updateRequestDetails(request);
- 
              List<UIProvider> uiProviders = session.getUIProviders();
  
              UIClassSelectionEvent classSelectionEvent = new UIClassSelectionEvent(

diff --cc server/src/com/vaadin/server/VaadinService.java
Simple merge

diff --cc server/src/com/vaadin/server/communication/UIInitHandler.java
Simple merge