Merge branch 'master' into 7.2

* 9b3df56 - (origin/master, origin/HEAD, master) Actually close push connection in disconnect() (#13716)
* f21c108 - Fix improper merge of 3d0ff32b from 7.1 to master (#13620)
* 3184af5 - Convert the ComboBoxClosePopupRetainText test to TB4 to avoid false failures.
* b136dd5 - Convert the AccordionClipsContent test to TB4 to avoid false failures.
* 50ea89e - Update Atmosphere client. (#13727)
* 78981f1 - Fix occasionally misplaced error indicators in Buttons (#13723)
* 8fb9121 - Fix misleading message. Close does not always mean reconnect
* 3d42856 - Removed irrelevant readme file

Change-Id: I1c871160a47da3e720f2b7d06c5ab3601a17d053