Merge remote-tracking branch 'origin/stable' into 5.3

Change-Id: I09992d60034fccf74c5f754ab88bebe8b8de5e45
Fix clang debug-and-release build

Under circumstances clang will leave code that calls the dead default
constructor of Attribute, which causes link time errors.

Change-Id: I265f5b6ee864737c8261cff1439d525000eed1ba
Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>
Fix letter-spacing in SVG

Qt incorrectly included letter-spacing when WebCore asked us to ignore
it which broke SVG rendering of letter-spaced text in the complex
font path.

Task-number: QTBUG-39601
Change-Id: Ia951e12ac5503955eb0e34e214219f9136c71465
Reviewed-by: Julien Brianceau <jbriance@cisco.com>
Reviewed-by: Michael Bruning <michael.bruning@digia.com>
Merge remote-tracking branch 'origin/stable' into 5.3

Change-Id: I182d18383f82025fa7b9cfe7f136cf590c01fb14
Merge remote-tracking branch 'origin/5.3.1' into phantomjs