Merge changes from origin/7.0

Merge changes from origin/7.0

892b8ba Do not submit TextArea value on enter in IE (#11982)
bd3f975 Properly disable combobox when parent is disabled (#10734)
1b85e59 Added missing import (#11982)
3c8a3bf Merge of properly focus clicked input element in Webkit (#11854, #11297)
d647d7a Ensure VBrowserFrame content is unloaded in IE (#11683)
08ba394 Disable drag&drop when source or target component is disabled, re-implementation of 6.8 fix for #11801
b01427a Change field types from LinkedHashSet back to HashSet to retain binary compatibility (#11432)
14ebd0d Fixed newlines

Change-Id: Icea535d8d5130e013327dd76a194e3910f533332