winrt: DNS lookup: don't have duplicate entries

Change-Id: I60ee29bd692f8e385080d4532a0e3230942a2cd3
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Doc: Various \note fixes in Qt namespace documentation.

-changed \note and \warning to "Note:" and "Warning:"
-\note and \warning split the table.
-other minor \note changes

Task-number: QTBUG-36972
Change-Id: I88042550cd01101e7225cd3b5f4e0115ea102ea9
Reviewed-by: Liang Qi <liang.qi@digia.com>
Reviewed-by: Martin Smith <martin.smith@digia.com>